                   FOR PUBLICATION
  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT

KRISTIN M. PERRY; SANDRA B.              
STIER; PAUL T. KATAMI; JEFFREY J.
ZARRILLO,
                 Plaintiffs-Appellees,
                 and
CITY AND COUNTY OF SAN
FRANCISCO,
                 Plaintiff-intervenor,
                  v.
ARNOLD SCHWARZENEGGER, in his
official capacity as Governor of
California; EDMUND G. BROWN, JR.,
in his official capacity as Attorney

                                         
General of California; MARK B.
HORTON in his official capacity as
Director of the California
Department of Public Health &
State Registrar of Vital Statistics;
LINETTE SCOTT, in her official
capacity as Deputy Director of
Health Information & Strategic
Planning for the California
Department of Public Health;
PATRICK O’CONNELL, in his official
capacity as Clerk-Recorder for the
County of Alameda; DEAN C.
LOGAN, in his official capacity as
Registrar-Recorder/County Clerk
for the County of Los Angeles,
                          Defendants,
                                         

                              573
574                PERRY v. SCHWARZENEGGER



                and                     
DENNIS HOLLINGSWORTH; GAIL J.
KNIGHT; MARTIN F. GUTIERREZ;                  No. 09-17241
HAK-SHING WILLIAM TAM; MARK
A. JANSSON; PROTECTMARRIAGE.
                                               D.C. No.
                                             3:09-cv-02292-
COM-YES ON 8, A PROJECT OF                        VRW
CALIFORNIA RENEWAL,
 Defendant-intervenors-Appellants.
                                        

KRISTIN M. PERRY; SANDRA B.             
STIER; PAUL T. KATAMI; JEFFREY J.
ZARRILLO,
                Plaintiffs-Appellees,
                 and
OUR FAMILY COALITION; LAVENDER
SENIORS OF THE EAST BAY;
PARENTS, FAMILIES, AND FRIENDS OF
                                        
LESBIANS AND GAYS, CITY AND
COUNTY OF SAN FRANCISCO,
    Plaintiff-intervenors-Appellees,
                  v.
ARNOLD SCHWARZENEGGER; EDMUND
G. BROWN, JR.; MARK B. HORTON;
LINETTE SCOTT; PATRICK
O’CONNELL; DEAN C. LOGAN,
                         Defendants,
                 and
                                        
                 PERRY v. SCHWARZENEGGER                575


DENNIS HOLLINGSWORTH; GAIL J.              No. 09-17551
KNIGHT; MARTIN F. GUTIERREZ;                  D.C. No.
HAK-SHING WILLIAM TAM; MARK                3:09-cv-02292-
A. JANSSON; PROTECTMARRIAGE.                    VRW
COM-YES ON 8, A PROJECT OF
CALIFORNIA RENEWAL,                           ORDER
 Defendant-intervenors-Appellants.          AMENDING
                                          OPINION AND
                                             DENYING
                                          PETITION FOR
                                         REHEARING AND
                                          REHEARING EN
                                            BANC AND
                                            AMENDED
                                             OPINION

      Appeal from the United States District Court
         for the Northern District of California
    Vaughn R. Walker, Chief District Judge, Presiding

                Argued and Submitted
         December 1, 2009—Pasadena, California

                Filed December 11, 2009
                Amended January 4, 2010

  Before: Kim McLane Wardlaw, Raymond C. Fisher and
            Marsha S. Berzon, Circuit Judges.

                 Opinion by Judge Fisher
                  PERRY v. SCHWARZENEGGER                 579
                         COUNSEL

Andrew P. Pugno, Law Offices of Andrew P. Pugno, Folsom,
California; Brian W. Raum and James A. Campbell, Alliance
Defense Fund, Scottsdale, Arizona; Charles J. Cooper
(argued), David H. Thompson, Howard C. Nielson, Jr., Nicole
J. Moss, Jesse Panuccio and Peter A. Patterson, Cooper and
Kirk, PLLC, Washington, D.C., for the defendant-intervenors-
appellants.

Theodore J. Boutrous, Jr. (argued), Rebecca Justice Lazarus,
Enrique A. Monagas, Gibson, Dunn & Crutcher LLP, Los
Angeles, California; Theodore B. Olson, Matthew D. McGill
and Amir C. Tayrani, Gibson, Dunn & Crutcher LLP, Wash-
ington, D.C., for the plaintiffs-appellees.

Stephen V. Bomse, Orrick, Herrington & Sutcliffe LLP, San
Francisco, California, Allan L. Schlosser and Elizabeth O.
Gill, ACLU Foundation of Northern California, for amicus
curiae American Civil Liberties Union of Northern California.

Robert H. Tyler and Jennifer Lynn Monk, Advocates for Faith
and Freedom, Murrieta, California, for amici curiae Schubert
Flint Public Affairs, Inc., Frank Schubert and Jeff Flint.


                          ORDER

  The opinion filed December 11, 2009 is amended, and the
amended opinion is filed concurrently with this Order.

  The panel has voted to deny the petition for rehearing and
rehearing en banc.

   A judge requested a vote on whether to rehear the matter
en banc, and the matter failed to receive a majority of the
votes of the nonrecused active judges in favor of en banc con-
sideration. Fed. R. App. P. 35.
580                PERRY v. SCHWARZENEGGER
   Appellees’ petition for rehearing and rehearing en banc,
filed December 24, 2009, is DENIED.

  No further petitions for rehearing will be permitted.

  IT IS SO ORDERED.


                          OPINION

FISHER, Circuit Judge:

   Proposition 8 amended the California Constitution to pro-
vide that only marriage between a man and a woman is valid
or recognized in California. Two same-sex couples filed this
action in the district court alleging that Proposition 8 violates
the Due Process and Equal Protection Clauses of the Four-
teenth Amendment. The official proponents of Proposition 8
(“Proponents”) intervened to defend the suit. Plaintiffs served
a request for production of documents on Proponents, seek-
ing, among other things, production of Proponents’ internal
campaign communications relating to campaign strategy and
advertising. Proponents objected to disclosure of the docu-
ments as barred by the First Amendment. In two orders, the
district court rejected Proponents’ claim of First Amendment
privilege. Proponents appealed both orders and, in the alterna-
tive, petitioned for a writ of mandamus directing the district
court to grant a protective order. We granted Proponents’
motion for stay pending appeal.

   We hold that the exceptional circumstances presented by
this case warrant issuance of a writ of mandamus. The free-
dom to associate with others for the common advancement of
political beliefs and ideas lies at the heart of the First Amend-
ment. Where, as here, discovery would have the practical
effect of discouraging the exercise of First Amendment asso-
ciational rights, the party seeking such discovery must dem-
                   PERRY v. SCHWARZENEGGER                  581
onstrate a need for the information sufficient to outweigh the
impact on those rights. Plaintiffs have not on the existing
record carried that burden in this case. We therefore grant
Proponents’ petition and direct the district court to enter an
appropriate protective order consistent with this opinion.

                       I.   BACKGROUND

   In November 2008, California voters approved Proposition
8, an initiative measure providing that “[o]nly marriage
between a man and a woman is valid or recognized in Califor-
nia.” Cal. Const. art. I, § 7.5. The California Supreme Court
has upheld Proposition 8 against several state constitutional
challenges. Strauss v. Horton, 207 P.3d 48, 63-64 (Cal. 2009).
Plaintiffs, two same-sex couples prohibited from marrying,
filed this 42 U.S.C. § 1983 action alleging “that Prop. 8,
which denies gay and lesbian individuals the right to marry
civilly and enter into the same officially sanctioned family
relationship with their loved ones as heterosexual individuals,
is unconstitutional under the Due Process and Equal Protec-
tion Clauses of the Fourteenth Amendment to the United
States Constitution.” Compl. ¶¶ 5, 7. They alleged among
other things that “[t]he disadvantage Prop. 8 imposes on gays
and lesbians is the result of disapproval or animus against a
politically unpopular group.” Id. ¶ 43. Defendants are a num-
ber of state officials responsible for the enforcement of Propo-
sition 8, including the Governor and the Attorney General. Id.
¶¶ 13-19. Plaintiffs seek declaratory and injunctive relief. Id.
¶ 8.

   After the Attorney General declined to defend the constitu-
tionality of Proposition 8, the district court granted a motion
by Proponents — the official proponents of Proposition 8 and
the official Proposition 8 campaign committee — to intervene
as defendants.

   Plaintiffs served requests for production of documents on
Proponents under Federal Rule of Civil Procedure 34. Plain-
tiffs’ eighth request sought:
582                  PERRY v. SCHWARZENEGGER
      All versions of any documents that constitute com-
      munications referring to Proposition 8, between you
      and any third party, including, without limitation,
      members of the public or the media.

The parties understand this request as encompassing, among
other things, Proponents’ internal campaign communications
concerning strategy and messaging.

   Proponents objected to the request as irrelevant, privileged
under the First Amendment and unduly burdensome and filed
a motion for a protective order. They argued that their internal
campaign communications, including draft versions of com-
munications never actually disseminated to the electorate at
large, were privileged under the First Amendment. They
offered evidence that the disclosure of internal strategy docu-
ments would burden political association rights by discourag-
ing individuals from participating in initiative campaigns and
by muting the exchange of ideas within those campaigns.
They asserted that the documents plaintiffs sought were irrele-
vant to the issues in this case, and even if they were relevant,
the First Amendment interests at stake outweighed plaintiffs’
need for the information.

   Plaintiffs opposed the motion for protective order. They
argued that their request was reasonably calculated to lead to
the discovery of admissible evidence concerning the purpose
of Proposition 8, as well as evidence concerning the rational-
ity and strength of Proponents’ purported state interests for
Proposition 8. They disputed Proponents’ contention that any
of the documents requested were privileged other than with
respect to the names of rank-and-file members of the cam-
paign, which they agreed to redact.

  In an October 1, 2009 order, the district court granted in
part and denied in part Proponents’ motion for a protective
order. The court denied Proponents’ claims of privilege.1 The
  1
  The district court also observed that Proponents had failed to produce
a privilege log required by Federal Rule of Civil Procedure
                      PERRY v. SCHWARZENEGGER                            583
court also determined that plaintiffs’ request was “reasonably
calculated to lead to the discovery of admissible evidence”
regarding voter intent, the purpose of Proposition 8 and
whether Proposition 8 advances a legitimate governmental
interest. The court said that “communications between propo-
nents and political consultants or campaign managers, even
about messages contemplated but not actually disseminated,
could fairly readily lead to admissible evidence illuminating
the messages disseminated to voters.”2

   Following the court’s October 1 order, Proponents submit-
ted a sample of documents potentially responsive to plaintiffs’
document request for in camera review, asserting that the
documents were both irrelevant and privileged. In a Novem-
ber 11, 2009 order following that review, the district court
again rejected Proponents’ argument that their internal cam-
paign communications were privileged under the First
Amendment:

     Proponents have not . . . identified any way in which
     the . . . privilege could protect the disclosure of cam-
     paign communications or the identities of high rank-

26(b)(5)(A)(ii). We agree that some form of a privilege log is required and
reject Proponents’ contention that producing any privilege log would
impose an unconstitutional burden.
   2
     The court indicated that plaintiffs’ request was
    appropriate to the extent it calls for (1) communications by and
    among proponents and their agents (at a minimum, Schubert Flint
    Public Affairs) concerning campaign strategy and (2) communi-
    cations by and among proponents and their agents concerning
    messages to be conveyed to voters, . . . without regard to whether
    the messages were actually disseminated or merely contemplated.
    In addition, communications by and among proponents with
    those who assumed a directorial or managerial role in the Prop
    8 campaign, like political consultants or ProtectMarriage.com’s
    treasurer and executive committee, among others, would appear
    likely to lead to discovery of admissible evidence.
584                  PERRY v. SCHWARZENEGGER
      ing members of the campaign. . . . If the . . . privilege
      identified by proponents protects anything, it is the
      identities of rank-and-file volunteers and similarly
      situated individuals.

Applying the usual discovery standards of Federal Rule of
Civil Procedure 26, the court determined that documents fall-
ing into the following categories were reasonably likely to
lead to the discovery of admissible evidence: documents relat-
ing to “messages or themes conveyed to voters through adver-
tising or direct messaging,” documents dealing “directly with
advertising or messaging strategy and themes” and documents
discussing voters’ “potential reactions” to campaign mes-
sages. The court ordered production of 21 of the 60 docu-
ments submitted for review.

  Proponents appealed from the October 1 and November 11
orders and, in the alternative, petitioned for a writ of manda-
mus. We granted Proponents’ motion for a stay pending
appeal. We now grant the petition for a writ of mandamus.

                        II.   JURISDICTION

   Proponents contend that we have jurisdiction on two bases.
First, they assert that the district court’s orders are appealable
under the collateral order doctrine. Second, they have peti-
tioned for issuance of a writ of mandamus.

   While this appeal was pending, the Supreme Court decided
Mohawk Industries, Inc. v. Carpenter, 558 U.S. ___ (Dec. 8,
2009), holding that discovery orders denying claims of
attorney-client privilege are not appealable under the collat-
eral order doctrine. After Mohawk, it is uncertain whether the
collateral order doctrine applies to discovery orders denying
claims of First Amendment privilege, as we shall explain.
Ultimately, we do not resolve the question here. Given the
uncertainty, we have decided instead to rely on mandamus to
review the district court’s rulings. We have repeatedly exer-
                    PERRY v. SCHWARZENEGGER                585
cised mandamus review when confronted with extraordinarily
important questions of first impression concerning the scope
of a privilege. As this case falls within that small class of
extraordinary cases, we exercise our supervisory mandamus
authority here.

               A.    Collateral Order Doctrine

   [1] We have jurisdiction to review “final decisions of the
district courts.” 28 U.S.C. § 1291. Under the collateral order
doctrine, a litigant may appeal “from a narrow class of deci-
sions that do not terminate the litigation, but must, in the
interest of ‘achieving a healthy legal system,’ nonetheless be
treated as ‘final.’ ” Digital Equip. Corp. v. Desktop Direct,
Inc., 511 U.S. 863, 867 (1994) (quoting Cobbledick v. United
States, 309 U.S. 323, 326 (1940)). To be immediately appeal-
able, a collateral decision “must conclusively determine the
disputed question, resolve an important issue completely sep-
arate from the merits of the action, and be effectively unre-
viewable on appeal from a final judgment.” Coopers &
Lybrand v. Livesay, 437 U.S. 463, 468 (1978).

   [2] The first prong is easily satisfied in this case. Taken
together, the October 1 and November 11 discovery orders
conclusively determined the scope of the First Amendment
privilege. The district court concluded that the privilege does
not extend to internal campaign communications and that it is
limited to the disclosure of identities of rank-and-file mem-
bers and other similarly situated individuals. Furthermore, in
the November 11 order, the district court conclusively deter-
mined that Proponents were required to produce 21 docu-
ments that, according to the court, were not privileged. See
United States v. Griffin, 440 F.3d 1138, 1141 (9th Cir. 2006)
(“[T]he district court’s order ‘conclusively determine[s] the
disputed question’ whether the government is entitled to read
the communications between Griffin and his wife for which
the [marital communications] privilege had been claimed.”).
586                PERRY v. SCHWARZENEGGER
   [3] The second prong is also satisfied. The overall scope of
the First Amendment privilege is a question of law that is
entirely separate from the merits of the litigation. In theory,
the application of the privilege to plaintiffs’ specific discovery
requests has some overlap with merits-related issues, such as
whether plaintiffs’ substantive claims are governed by strict
scrutiny or rational basis review and whether plaintiffs may
rely on certain types of evidence to prove that Proposition 8
was enacted for an improper purpose. We need not, and do
not, delve into those questions in this appeal, however. We
assume without deciding that the district court’s rulings on
those questions are correct. There is, therefore, no “overlap”
between the issues we must decide in this appeal and the “fac-
tual and legal issues of the underlying dispute.” Van Cauwen-
berghe v. Biard, 486 U.S. 517, 529 (1988).

   [4] It is the third prong that poses the most difficult ques-
tion. Under Mohawk, the third prong turns on whether rulings
on First Amendment privilege are, as a class, effectively
reviewable on appeal from final judgment — i.e., “whether
delaying review until the entry of final judgment ‘would
imperil a substantial public interest’ or ‘some particular value
of a high order.’ ” Mohawk, 558 U.S. at ___, slip op. 6 (quot-
ing Will v. Hallock, 546 U.S. 345, 352-53 (2006)). In
Mohawk, the Court concluded that this prong was not satisfied
with respect to the class of rulings addressing invocation of
the attorney-client privilege during discovery. This was so
because the typical ruling on the attorney-client privilege will
involve only “the routine application of settled legal princi-
ples.” Id. at 8. Denying immediate appellate review would
have no “discernible chill” because “deferring review until
final judgment does not meaningfully reduce the ex ante
incentives for full and frank consultations between clients and
counsel.” Id. There being no discernible harm to the public
interest, the remaining harm from an erroneous ruling (the
harm to the individual litigant of having confidential commu-
nications disclosed) could be adequately, if imperfectly, reme-
died by review after final judgment: “Appellate courts can
                   PERRY v. SCHWARZENEGGER                   587
remedy the improper disclosure of privileged material in the
same way they remedy a host of other erroneous evidentiary
rulings: by vacating an adverse judgment and remanding for
a new trial in which the protected material and its fruits are
excluded from evidence.” Id.

   Some of Mohawk’s reasoning carries over to the First
Amendment privilege. There are, however, several reasons
the class of rulings involving the First Amendment privilege
differs in ways that matter to a collateral order appeal analysis
from those involving the attorney-client privilege. First, this
case concerns a privilege of constitutional dimensions. The
right at issue here — freedom of political association — is of
a high order. The constitutional nature of the right is not dis-
positive of the collateral order inquiry, see, e.g., Flanagan v.
United States, 465 U.S. 259, 267-68 (1984), but it factors into
our analysis. Second, the public interest associated with this
class of cases is of greater magnitude than that in Mohawk.
Compelled disclosures concerning protected First Amend-
ment political associations have a profound chilling effect on
the exercise of political rights. See, e.g., Gibson v. Florida
Legislative Investigation Comm., 372 U.S. 539, 557 (1963)
(underscoring the substantial “deterrent and ‘chilling’ effect
on the free exercise of constitutionally enshrined rights of free
speech, expression, and association” resulting from compelled
disclosure of political associations). Third, unlike the
attorney-client privilege, the First Amendment privilege is
rarely invoked. Collateral review of the First Amendment
privilege, therefore, does not implicate significant “institu-
tional costs.” Mohawk, 558 U.S. ___, slip op. at 11. Cf. id.
(“Permitting parties to undertake successive, piecemeal
appeals of all adverse attorney-client rulings would unduly
delay the resolution of district court litigation and needlessly
burden the Courts of Appeals.”). Finally, we observe that
Mohawk expressly reserved whether the collateral order doc-
trine applies in connection with other privileges. See id. at 12
n.4.
588                PERRY v. SCHWARZENEGGER
   [5] In light of these considerations, whether Mohawk
should be extended to the First Amendment privilege presents
a close question. The distinctions between the First Amend-
ment privilege and the attorney-client privilege — a constitu-
tional basis, a heightened public interest, rarity of invocation
and a long recognized chilling effect — are not insubstantial.
Given our uncertainty about the availability of collateral order
review after Mohawk, we nonetheless assume without decid-
ing that discovery orders denying claims of First Amendment
privilege are not reviewable under the collateral order doc-
trine. Rather, we rely on mandamus to hear this exceptionally
important case, for reasons we now explain.

                       B.   Mandamus

  The exceptional circumstances presented by this case war-
rant exercising our jurisdiction under the All Writs Act, 28
U.S.C. § 1651(a). See Cheney v. U.S. Dist. Court, 542 U.S.
367, 380 (2004); City of Las Vegas v. Foley, 747 F.2d 1294,
1296-97 (9th Cir. 1984).

   [6] “The writ of mandamus is an ‘extraordinary’ remedy
limited to ‘extraordinary’ causes.” Burlington Northern &
Santa Fe Ry. Co. v. U.S. Dist. Court, 408 F.3d 1142, 1146
(9th Cir. 2005) (quoting Cheney, 542 U.S. at 380). In Bauman
v. United States District Court, 557 F.2d 650 (9th Cir. 1977),
we established five guidelines to determine whether manda-
mus is appropriate in a given case: (1) whether the petitioner
has no other means, such as a direct appeal, to obtain the
desired relief; (2) whether the petitioner will be damaged or
prejudiced in any way not correctable on appeal; (3) whether
the district court’s order is clearly erroneous as a matter of
law; (4) whether the district court’s order is an oft repeated
error or manifests a persistent disregard of the federal rules;
and (5) whether the district court’s order raises new and
important problems or issues of first impression. Id. at 654-
55. “The factors serve as guidelines, a point of departure for
our analysis of the propriety of mandamus relief.” Admiral
                   PERRY v. SCHWARZENEGGER                   589
Ins. Co. v. U.S. Dist. Court, 881 F.2d 1486, 1491 (9th Cir.
1989). “Not every factor need be present at once.” Burlington,
408 F.3d at 1146. “However, the absence of the third factor,
clear error, is dispositive.” Id.

   [7] Mandamus is appropriate to review discovery orders
“when particularly important interests are at stake.” 16 C.
Wright, A. Miller, & E. Cooper, Federal Practice and Proce-
dure § 3935.3 (2d ed. 2009) (hereinafter Wright & Miller).
Although “the courts of appeals cannot afford to become
involved with the daily details of discovery,” we may rely on
mandamus to resolve “new questions that otherwise might
elude appellate review” or “to protect important or clear
claims of privilege.” Id.; see Mohawk, 558 U.S. ___, slip op.
9 (“[L]itigants confronted with a particularly injurious or
novel privilege ruling have several potential avenues of
review apart from collateral order appeal. . . . [A] party may
petition the court of appeals for a writ of mandamus.”). In
Schlagenhauf v. Holder, 379 U.S. 104 (1964), for example,
the Supreme Court relied on mandamus to answer the novel
question whether Federal Rule of Civil Procedure 35 autho-
rized the physical and mental examination of a defendant.
“The opinion affords strong support for the use of supervisory
or advisory mandamus to review a discovery question that
raises a novel and important question of power to compel dis-
covery, or that reflects substantial uncertainty and confusion
in the district courts.” Wright & Miller § 3935.3.

   [8] Consistent with Schlagenhauf, we have exercised man-
damus jurisdiction to review discovery orders raising particu-
larly important questions of first impression, especially when
called upon to define the scope of an important privilege. In
Admiral Insurance, for example, we granted the mandamus
petition to resolve “a significant issue of first impression con-
cerning the proper scope of the attorney-client privilege.” 881
F.2d at 1488. Taiwan v. United States District Court, 128
F.3d 712 (9th Cir. 1997), likewise involved review of another
issue of first impression — the scope of testimonial immunity
590                 PERRY v. SCHWARZENEGGER
under the Taiwan Relations Act. Id. at 714. Finally, in Foley,
we exercised our mandamus authority to address an “impor-
tant issue of first impression” in a context similar to that here
— whether legislators can be deposed to determine their sub-
jective motives for enacting a law challenged as violative of
the First Amendment. 747 F.2d at 1296.

   [9] Here, too, we are asked to address an important issue
of first impression — the scope of the First Amendment privi-
lege against compelled disclosure of internal campaign com-
munications. Considering the Bauman factors, we conclude
that this is an extraordinary case in which mandamus review
is warranted.

   Assuming, as we are, that no collateral order appeal is
available, the first factor is present: “A discovery order . . . is
interlocutory and non-appealable” under 28 U.S.C. §§ 1291,
1292(a)(1) and 1292(b). Foley, 747 F.2d at 1297; see also id.
(“Mandamus review has been held to be appropriate for dis-
covery matters which otherwise would be reviewable only on
direct appeal after resolution on the merits.”). In Admiral
Insurance, for example, we held that the first Bauman factor
was satisfied because “the petitioner lacks an alternative ave-
nue for relief.” 881 F.2d at 1488.

   The second factor also supports mandamus. A post-
judgment appeal would not provide an effective remedy, as
“no such review could prevent the damage that [Proponents]
allege they will suffer or afford effective relief therefrom.” In
re Cement Antitrust Litig., 688 F.2d 1297, 1302 (9th Cir.
1982); see Star Editorial, Inc. v. U.S. Dist. Court, 7 F.3d 856,
859 (9th Cir. 1993) (“[I]f the district court erred in compelling
disclosure, any damage the [newspaper] suffered would not
be correctable on appeal.”); Admiral Ins., 881 F.2d at 1491
(holding that the second factor was satisfied in view of “the
irreparable harm a party likely will suffer if erroneously
required to disclose privileged materials or communica-
tions”). One injury to Proponents’ First Amendment rights is
                    PERRY v. SCHWARZENEGGER                     591
the disclosure itself. Regardless of whether they prevail at
trial, this injury will not be remediable on appeal. See In re
Cement Antitrust Litig., 688 F.2d at 1302 (“[A] post-judgment
reversal on appeal could not provide a remedy for those inju-
ries.”). If Proponents prevail at trial, vindication of their rights
will be not merely delayed but also entirely precluded. See id.
(“Moreover, whatever collateral injuries petitioners suffer will
have been incurred even if they prevail fully at trial and thus
have no right to appeal from the final judgment.”).

   Under the second factor, we also consider the substantial
costs imposed on the public interest. The district court applied
an unduly narrow conception of First Amendment privilege.
Under that interpretation, associations that support or oppose
initiatives face the risk that they will be compelled to disclose
their internal campaign communications in civil discovery.
This risk applies not only to the official proponents of initia-
tives and referendums, but also to the myriad social, eco-
nomic, religious and political organizations that publicly
support or oppose ballot measures. The potential chilling
effect on political participation and debate is therefore sub-
stantial, even if the district court’s error were eventually cor-
rected on appeal from final judgment. In this sense, our
concerns in this case mirror those we articulated in Foley,
where the district court denied the city’s motion for a protec-
tive order to prevent plaintiffs from deposing city officials
about their reasons for passing a zoning ordinance. Absent
swift appellate review, we explained, “legislators could be
deposed in every case where the governmental interest in a
regulation is challenged.” 747 F.2d at 1296. More concerning
still is the possibility that if Proponents ultimately prevail in
the district court, there would be no appeal at all of the
court’s construction of the First Amendment privilege.
Declining to exercise our mandamus jurisdiction in this case,
therefore, “ ‘would imperil a substantial public interest’ or
‘some particular value of a high order.’ ” Mohawk, 558 U.S.
at ___, slip op. at 6 (quoting Will, 546 U.S. at 352-53).
592                PERRY v. SCHWARZENEGGER
   The third factor, clear error, is also met. As discussed
below, we are firmly convinced that the district court erred by
limiting the First Amendment privilege to “the identities of
rank-and-file volunteers and similarly situated individuals”
and affording no greater protection to Proponents’ internal
communications than the generous relevance standard of Fed-
eral Rule of Civil Procedure 26. See In re Cement Antitrust
Litig., 688 F.2d at 1306-07 (“[W]hen we are firmly convinced
that a district court has erred in deciding a question of law, we
may hold that the district court’s ruling is ‘clearly erroneous
as a matter of law as that term is used in mandamus analy-
sis.’ ”) (quoting Bauman, 557 F.2d at 660). “[Plaintiffs’] need
for information is only one facet of the problem.” Cheney,
542 U.S. at 385. A political campaign’s communications and
activities “encompass a vastly wider range of sensitive materi-
al” protected by the First Amendment than would be true in
the normal discovery context. Id. at 381; see Foley, 747 F.2d
at 1298-99. Thus, “[a]n important factor weighing in the
opposite direction is the burden imposed by the discovery
orders. This is not a routine discovery dispute.” Cheney, 542
U.S. at 385.

   Finally, the fifth factor weighs in favor of exercise of our
supervisory mandamus authority: we are faced with the need
to resolve a significant question of first impression. See, e.g.,
Schlagenhauf, 379 U.S. at 110-11 (finding mandamus juris-
diction appropriate where there was an issue of first impres-
sion concerning the district court’s application of Federal
Rule of Civil Procedure 35 in a new context); Foley, 747 F.2d
at 1296. As these cases — and the very existence of the fifth
Bauman factor, whether the issue presented is one of first
impression — illustrate, the necessary “clear error” factor
does not require that the issue be one as to which there is
established precedent. Moreover, this novel and important
question may repeatedly evade review because of the collat-
eral nature of the discovery ruling. See In re Cement Antitrust
Litig., 688 F.2d at 1304-05 (“[A]n important question of first
impression will evade review unless it is considered under our
                     PERRY v. SCHWARZENEGGER                      593
supervisory mandamus authority. Moreover, that question
may continue to evade review in other cases as well.”); Colo-
nial Times, Inc. v. Gasch, 509 F.2d 517, 524-26 (D.C. Cir.
1975) (exercising mandamus jurisdiction to correct an error in
a discovery order).

   [10] In sum, this is an important case for exercise of our
mandamus jurisdiction: adequate, alternative means of review
are unavailable; the harm to Proponents and to the public
interest is not correctable on appeal; the district court’s dis-
covery order is clearly erroneous; and it presents a significant
issue of first impression that may repeatedly evade review. As
in Foley, a closely analogous case, these factors “remove this
case from the category of ordinary discovery orders where
interlocutory appellate review is unavailable, through manda-
mus or otherwise.” Cheney, 542 U.S. at 381. Accordingly, we
hold that the exercise of our supervisory mandamus authority
is appropriate.

              III.   FIRST AMENDMENT PRIVILEGE3

                                 A.

   [11] “Effective advocacy of both public and private points
of view, particularly controversial ones, is undeniably
enhanced by group association.” NAACP v. Alabama, 357
U.S. 449, 460 (1958); see also Roberts v. U.S. Jaycees, 468
U.S. 609, 622 (1984) (“An individual’s freedom to speak, to
worship, and to petition the government for the redress of
grievances could not be vigorously protected from interfer-
ence by the State unless a correlative freedom to engage in
group effort toward those ends were not also guaranteed.”).
Thus, “[t]he First Amendment protects political association as
well as political expression,” Buckley v. Valeo, 424 U.S. 1, 15
(1976), and the “freedom to associate with others for the com-
  3
   We review de novo a determination of privilege. United States v.
Ruehle, 583 F.3d 600, 606 (9th Cir. 2009) (attorney-client privilege).
594                   PERRY v. SCHWARZENEGGER
mon advancement of political beliefs and ideas is . . . pro-
tected by the First and Fourteenth Amendments.” Kusper v.
Pontikes, 414 U.S. 51, 56-57 (1973). “The right to associate
for expressive purposes is not, however, absolute.” Roberts,
468 U.S. at 623. “Infringements on that right may be justified
by regulations adopted to serve compelling state interests,
unrelated to the suppression of ideas, that cannot be achieved
through means significantly less restrictive of associational
freedoms.” Id.

   [12] The government may abridge the freedom to associate
directly, or “abridgement of such rights, even though unin-
tended, may inevitably follow from varied forms of govern-
mental action.” NAACP, 357 U.S. at 461. Thus, the
government must justify its actions not only when it imposes
direct limitations on associational rights, but also when gov-
ernmental action “would have the practical effect ‘of discour-
aging’ the exercise of constitutionally protected political
rights.” Id. (quoting Am. Commc’ns Ass’n v. Douds, 339 U.S.
382, 393 (1950)). Such actions have a chilling effect on, and
therefore infringe, the exercise of fundamental rights. Accord-
ingly, they “must survive exacting scrutiny.” Buckley, 424
U.S. at 64.

   [13] The compelled disclosure of political associations can
have just such a chilling effect. See id. (“[W]e have repeatedly
found that compelled disclosure, in itself, can seriously
infringe on privacy of association and belief guaranteed by
the First Amendment.”); AFL-CIO v. FEC, 333 F.3d 168, 175
(D.C. Cir. 2003) (“The Supreme Court has long recognized
that compelled disclosure of political affiliations and activities
can impose just as substantial a burden on First Amendment
rights as can direct regulation.”).4 Disclosures of political
   4
     See, e.g., NAACP, 357 U.S. at 461-64 (prohibiting the compelled dis-
closure of the NAACP membership lists); Bates v. City of Little Rock, 361
U.S. 516, 525-27 (1960) (same); DeGregory v. Attorney Gen., 383 U.S.
825, 828-30 (1966) (prohibiting the state from compelling defendant to
discuss his association with the Communist Party); Buckley, 424 U.S. at
63-74 (recognizing the burden but upholding the compelled disclosure of
campaign contributor information under the “exacting scrutiny” standard).
                       PERRY v. SCHWARZENEGGER                          595
affiliations and activities that have a “deterrent effect on the
exercise of First Amendment rights” are therefore subject to
this same “exacting scrutiny.” Buckley, 424 U.S. at 64-65. A
party who objects to a discovery request as an infringement
of the party’s First Amendment rights is in essence asserting
a First Amendment privilege. See, e.g., Black Panther Party
v. Smith, 661 F.2d 1243, 1264 (D.C. Cir. 1981), cert. granted
and vacated as moot, 458 U.S. 1118 (1982); see also Fed. R.
Civ. P. 26(b)(1) (“Parties may obtain discovery regarding any
nonprivileged matter that is relevant to any party’s claim or
defense[.]”) (emphasis added).5

   In this circuit, a claim of First Amendment privilege is sub-
ject to a two-part framework. The party asserting the privilege
“must demonstrate . . . a ‘prima facie showing of arguable
first amendment infringement.’ ” Brock v. Local 375, Plumb-
ers Int’l Union of Am., 860 F.2d 346, 349-50 (9th Cir. 1988)
(quoting United States v. Trader’s State Bank, 695 F.2d 1132,
1133 (9th Cir. 1983) (per curiam)). “This prima facie showing
requires appellants to demonstrate that enforcement of the
[discovery requests] will result in (1) harassment, membership
withdrawal, or discouragement of new members, or (2) other
consequences which objectively suggest an impact on, or
‘chilling’ of, the members’ associational rights.” Id. at 350.6
   5
     This privilege applies to discovery orders “even if all of the litigants
are private entities.” Grandbouche v. Clancy, 825 F.2d 1463, 1466 (10th
Cir. 1987); see also Adolph Coors Co. v. Wallace, 570 F. Supp. 202, 208
(N.D. Cal. 1983) (“[A] private litigant is entitled to as much solicitude to
its constitutional guarantees of freedom of associational privacy when
challenged by another private party, as when challenged by a government
body.”) (footnote omitted).
   6
     A protective order limiting the dissemination of disclosed associational
information may mitigate the chilling effect and could weigh against a
showing of infringement. The mere assurance that private information will
be narrowly rather than broadly disseminated, however, is not dispositive.
See Dole v. Serv. Employees Union, AFL-CIO, Local 280, 950 F.2d 1456,
1461 (9th Cir. 1991) (“[N]either letter suggests that it is the unlimited
nature of the disclosure of the Union minutes that underlies the member’s
unwillingness to attend future meetings. Rather, both letters exhibit a con-
cern for the consequences that would flow from any disclosure of the con-
tents of the minutes to the government or any government official.”).
596                  PERRY v. SCHWARZENEGGER
“If appellants can make the necessary prima facie showing,
the evidentiary burden will then shift to the government . . .
[to] demonstrate that the information sought through the [dis-
covery] is rationally related to a compelling governmental
interest . . . [and] the ‘least restrictive means’ of obtaining the
desired information.” Id.; see also Dole v. Serv. Employees
Union, AFL-CIO, Local 280, 950 F.2d 1456, 1459-61 (9th
Cir. 1991) (same). More specifically, the second step of the
analysis is meant to make discovery that impacts First
Amendment associational rights available only after careful
consideration of the need for such discovery, but not necessar-
ily to preclude it. The question is therefore whether the party
seeking the discovery “has demonstrated an interest in obtain-
ing the disclosures it seeks . . . which is sufficient to justify
the deterrent effect . . . on the free exercise . . . of [the] consti-
tutionally protected right of association.” NAACP, 357 U.S. at
463.

   To implement this standard, we “balance the burdens
imposed on individuals and associations against the signifi-
cance of the . . . interest in disclosure,” AFL-CIO v. FEC, 333
F.3d at 176, to determine whether the “interest in disclosure
. . . outweighs the harm,” Buckley, 424 U.S. at 72. This bal-
ancing may take into account, for example, the importance of
the litigation, see Dole, 950 F.2d at 1461 (“[T]here is little
doubt that the . . . purpose of investigating possible criminal
violations . . . serves a compelling governmental interest[.]”);
the centrality of the information sought to the issues in the
case, see NAACP, 357 U.S. at 464-65; Grandbouche v.
Clancy, 825 F.2d 1463, 1466 (10th Cir. 1987); Black Panther
Party, 661 F.2d at 1268; the existence of less intrusive means
of obtaining the information, see Grandbouche, 825 F.2d at
1466; Black Panther Party, 661 F.2d at 1268; and the sub-
stantiality of the First Amendment interests at stake, see Buck-
ley, 424 U.S. at 71 (weighing the seriousness of “the threat to
the exercise of First Amendment rights” against the substanti-
ality of the state’s interest); Black Panther Party, 661 F.2d at
1267 (“The argument in favor of upholding the claim of privi-
                      PERRY v. SCHWARZENEGGER                        597
lege will ordinarily grow stronger as the danger to rights of
expression and association increases.”).7 Importantly, the
party seeking the discovery must show that the information
sought is highly relevant to the claims or defenses in the liti-
gation — a more demanding standard of relevance than that
under Federal Rule of Civil Procedure 26(b)(1). The request
must also be carefully tailored to avoid unnecessary interfer-
ence with protected activities, and the information must be
otherwise unavailable.

   Before we apply these rules to the discovery at issue on this
appeal, we address the district court’s apparent conclusion
that the First Amendment privilege, as a categorical matter,
does not apply to the disclosure of internal campaign commu-
nications.

                                   B.

   [14] The district court concluded that “[i]f the . . . privilege
identified by proponents protects anything, it is the identities
of rank-and-file volunteers and similarly situated individuals,”
and said that “Proponents have not . . . identified a way in
which the . . . privilege could protect the disclosure of cam-
paign communications.” The First Amendment privilege,
however, has never been limited to the disclosure of identities
of rank-and-file members. See, e.g., DeGregory, 383 U.S. at
828 (applying the privilege to “the views expressed and ideas
advocated” at political party meetings); Dole, 950 F.2d at
1459 (applying privilege to statements “of a highly sensitive
and political character” made at union membership meetings).
The existence of a prima facie case turns not on the type of
information sought, but on whether disclosure of the informa-
tion will have a deterrent effect on the exercise of protected
activities. See NAACP, 357 U.S. at 460-61; Brock, 860 F.2d
  7
   Courts generally apply some combination of these factors. See, e.g., In
re Motor Fuel Temperature Sales Practices Litig., 258 F.R.D. 407, 412-15
(D. Kan. 2009); Adolph Coors Co., 570 F. Supp. at 208.
598                    PERRY v. SCHWARZENEGGER
at 349-50. We have little difficulty concluding that disclosure
of internal campaign communications can have such an effect
on the exercise of protected activities.

   [15] First, the disclosure of such information can have a
deterrent effect on participation in campaigns. There is no
question that participation in campaigns is a protected activ-
ity. See San Francisco County Democratic Cent. Comm. v.
Eu, 826 F.2d 814, 827 (9th Cir. 1987) (“’[T]he right of indi-
viduals to associate for the advancement of political beliefs’
is fundamental.”) (quoting Williams v. Rhodes, 393 U.S. 23,
30 (1968)). Compelled disclosure of internal campaign infor-
mation can deter that participation. See Buckley, 424 U.S. at
68 (“It is undoubtedly true that public disclosure of contribu-
tions to candidates and political parties will deter some indi-
viduals who otherwise might contribute.”); In re Motor Fuel
Temperature Sales Practices Litig., 258 F.R.D. 407, 414 (D.
Kan. 2009) (holding that disclosure of “trade associations’
internal communications and evaluations about advocacy of
their members’ positions on contested political issues” might
reasonably “interfere with the core of the associations’ activi-
ties by inducing members to withdraw . . . or dissuading oth-
ers from joining”).8

  [16] Second, disclosure of internal campaign information
can have a deterrent effect on the free flow of information
within campaigns. Implicit in the right to associate with others
to advance one’s shared political beliefs is the right to
exchange ideas and formulate strategy and messages, and to
do so in private.9 Compelling disclosure of internal campaign
communications can chill the exercise of these rights.
  8
     In addition to discouraging individuals from joining campaigns, the
threat that internal campaign communications will be disclosed in civil lit-
igation can discourage organizations from joining the public debate over
an initiative. See Letter brief of Amicus Curiae American Civil Liberties
Union of Northern California, at 2 (explaining that the ACLU’s internal
campaign information has been subpoenaed in this case).
   9
     We derive this conclusion from cases that have recognized the right of
associations to be free of infringements in their internal affairs. The free-
                       PERRY v. SCHWARZENEGGER                          599
   In identifying two ways in which compelled disclosure of
internal campaign communications can deter protected activi-
ties — by chilling participation and by muting the internal
exchange of ideas — we do not suggest this is an exhaustive
list. Disclosures of the sort challenged here could chill pro-
tected activities in other ways as well.10 We cite these two

dom of members of a political association to deliberate internally over
strategy and messaging is an incident of associational autonomy. We rec-
ognized this right in San Francisco County Democratic Central Commit-
tee v. Eu, where we said that “the right of association would be hollow
without a corollary right of self-governance.” 826 F.2d at 827. “[T]here
must be a right not only to form political associations but to organize and
direct them in the way that will make them most effective.” Id. (quoting
Ripon Soc’y Inc. v. Nat’l Republican Party, 525 F.2d 567, 585 (D.C. Cir.
1975) (en banc)) (internal quotation marks omitted); see also Tashjian v.
Republican Party of Conn., 479 U.S. 208, 224 (1986) (“The Party’s deter-
mination of the boundaries of its own association, and of the structure
which best allows it to pursue its political goals, is protected by the Con-
stitution.”); Eu v. San Francisco County Democratic Cent. Comm., 489
U.S. 214, 231 n.21 (1989) (“By regulating the identity of the parties’ lead-
ers, the challenged statutes may also color the parties’ message and inter-
fere with the parties’ decisions as to the best means to promote that
message.”). The government may not “interfere with a [political] party’s
internal affairs” absent a “compelling state interest.” Eu, 489 U.S. at 231.
Associations, no less than individuals, have the right to shape their own
messages. See McIntyre v. Ohio Elections Comm’n, 514 U.S. 334, 342,
348 (1995) (striking down a state law prohibiting anonymous pamphle-
teering in part because the First Amendment includes a speaker’s right to
choose a manner of expression that she believes will be most persuasive);
AFL-CIO v. FEC, 333 F.3d at 177 (“[E]xtensive interference with political
groups’ internal operations and with their effectiveness . . . implicate[s]
significant First Amendment interests in associational autonomy.”).
   10
      See AFL-CIO v. FEC, 333 F.3d at 176-77 (“[T]he AFL-CIO and DNC
affidavits charge that disclosing detailed descriptions of training programs,
member mobilization campaigns, polling data, and state-by-state strategies
will directly frustrate the organizations’ ability to pursue their political
goals effectively by revealing to their opponents ‘activities, strategies and
tactics [that] we have pursued in subsequent elections and will likely fol-
low in the future.’ ”); In re Motor Fuel Temperature Sales Practices Litig.,
258 F.R.D. at 415 (“Disclosure of the associations’ evaluations of possible
lobbying and legislative strategy certainly could be used by plaintiffs to
gain an unfair advantage over defendants in the political arena.”).
600                PERRY v. SCHWARZENEGGER
examples for purposes of illustration only, and because they
are relevant to the assertions of privilege made by Proponents
here.

                               C.

   [17] In this case, Proponents have made “a ‘prima facie
showing of arguable first amendment infringement’ ” by dem-
onstrating “consequences which objectively suggest an impact
on, or ‘chilling’ of, . . . associational rights.” Brock, 860 F.2d
at 349-50 (quoting Trader’s State Bank, 695 F.2d at 1133).
They presented declarations from several individuals attesting
to the impact compelled disclosure would have on participa-
tion and formulation of strategy. For example, Mark Jansson,
a member of ProtectMarriage.com’s ad hoc executive com-
mittee, stated:

      I can unequivocally state that if the personal, non-
      public communications I have had regarding this
      ballot initiative — communications that expressed
      my personal political and moral views — are ordered
      to be disclosed through discovery in this matter, it
      will drastically alter how I communicate in the
      future. . . .

      I will be less willing to engage in such communica-
      tions knowing that my private thoughts on how to
      petition the government and my private political and
      moral views may be disclosed simply because of my
      involvement in a ballot initiative campaign. I also
      would have to seriously consider whether to even
      become an official proponent again.

Although the evidence presented by Proponents is lacking in
particularity, it is consistent with the self-evident conclusion
that important First Amendment interests are implicated by
the plaintiffs’ discovery request. The declaration creates a rea-
sonable inference that disclosure would have the practical
                      PERRY v. SCHWARZENEGGER                         601
effects of discouraging political association and inhibiting
internal campaign communications that are essential to effec-
tive association and expression. See Dole, 950 F.2d at 1459-
61 (holding that the union satisfied its prima facie burden by
submitting the declarations of two members who said they
would no longer participate in union membership meetings if
the disclosure of the minutes of the meetings were permitted).
A protective order limiting dissemination of this information
will ameliorate but cannot eliminate these threatened harms.
Proponents have therefore made a prima facie showing that
disclosure could have a chilling effect on protected activities.
The chilling effect is not as serious as that involved in cases
such as NAACP v. Alabama, 357 U.S. 449 (1958), but neither
is it insubstantial. See AFL-CIO v. FEC, 333 F.3d at 176
(“Although we agree that the evidence in this case is far less
compelling than the evidence presented in cases involving
groups whose members had been subjected to violence, eco-
nomic reprisals, and police or private harassment, that differ-
ence speaks to the strength of the First Amendment interests
asserted, not to their existence.”) (citations omitted).

    [18] The Proponents having made a prima facie showing of
infringement, the evidentiary burden shifts to the plaintiffs to
demonstrate a sufficient need for the discovery to counterbal-
ance that infringement. The district court did not apply this
heightened relevance test. Rather, having determined that the
First Amendment privilege does not apply to the disclosure of
internal campaign communications except to protect the iden-
tities of rank-and-file members and volunteers, the court
applied the Rule 26 standard of reasonably calculated to lead
to the discovery of admissible evidence. We agree with the
district court that plaintiffs’ request satisfies the Rule 26 stan-
dard. Plaintiffs’ request is reasonably calculated to lead to the
discovery of admissible evidence on the issues of voter intent
and the existence of a legitimate state interest.11 Such discov-
  11
    The parties dispute whether plaintiffs’ substantive claims are governed
by strict scrutiny or rational basis review. They also disagree about what
types of evidence may be relied upon to demonstrate voter intent. These
issues are beyond the scope of this appeal. We assume without deciding
that the district court has decided these questions correctly.
602                   PERRY v. SCHWARZENEGGER
ery might help to identify messages actually conveyed to vot-
ers. See Washington v. Seattle Sch. Dist. No. 1, 458 U.S. 457,
471 (1982) (considering statements made by proponents dur-
ing an initiative campaign to determine whether voters
adopted an initiative for an improper purpose). It also might
lead to the discovery of evidence showing that Proponents’
campaign messages were designed to “appeal[ ] to the . . .
biases of the voters.” Id. at 463 (quoting Seattle Sch. Dist. No.
1 v. Washington, 473 F. Supp. 996, 1009 (W.D. Wash.
1979)). It might reasonably lead to the discovery of evidence
undermining or impeaching Proponents’ claims that Proposi-
tion 8 serves legitimate state interests. See Romer v. Evans,
517 U.S. 620, 635 (1996) (“[A] law must bear a rational rela-
tionship to a legitimate governmental purpose.”).

   The Rule 26 standard, however, fails to give sufficient
weight to the First Amendment interests at stake. Given Pro-
ponents’ prima facie showing of infringement, we must apply
the First Amendment’s more demanding heightened relevance
standard. Doing so, we cannot agree that plaintiffs have
“demonstrated an interest in obtaining the disclosures . . .
which is sufficient to justify the deterrent effect . . . on the
free exercise . . . of [the] constitutionally protected right of
association.” NAACP, 357 U.S. at 463. Plaintiffs can obtain
much of the information they seek from other sources, with-
out intruding on protected activities. Proponents have already
agreed to produce all communications actually disseminated
to voters, including “communications targeted to discrete
voter groups.”12 Whether campaign messages were designed
  12
    We emphasize that our holding is limited to private, internal cam-
paign communications concerning the formulation of campaign strategy
and messages. See In re Motor Fuel Temperature Sales Practices Litig.,
258 F.R.D. at 415 (“The court wishes to make clear that defendants have
met their prima facie burden only with respect to the associations’ internal
evaluations of lobbying and legislation, strategic planning related to advo-
cacy of their members’ positions, and actual lobbying on behalf of mem-
bers. Any other communications to, from, or within trade associations are
                       PERRY v. SCHWARZENEGGER                           603
to appeal to voters’ animosity toward gays and lesbians is a
question that appears to be susceptible to expert testimony,
without intruding into private aspects of the campaign.
Whether Proposition 8 bears a rational relationship to a legiti-
mate state interest is primarily an objective inquiry.

   In sum, although the First Amendment interests at stake
here are not as weighty as in some of the membership list
cases, and harms can be mitigated in part by entry of a protec-
tive order, Proponents have shown that discovery would
likely have a chilling effect on political association and the
formulation of political expression. On the other side of the
ledger, plaintiffs have shown that the information they seek is

not deemed protected under the First Amendment associational privi-
lege.”).
   Our holding is therefore limited to communications among the core
group of persons engaged in the formulation of campaign strategy and
messages. We leave it to the district court, which is best acquainted with
the facts of this case and the structure of the “Yes on 8” campaign, to
determine the persons who logically should be included in light of the
First Amendment associational interests the privilege is intended to pro-
tect.
   Our holding is also limited to private, internal communications regard-
ing formulation of strategy and messages. It certainly does not apply to
documents or messages conveyed to the electorate at large, discrete groups
of voters or individual voters for purposes such as persuasion, recruitment
or motivation — activities beyond the formulation of strategy and mes-
sages. Similarly, communications soliciting active support from actual or
potential Proposition 8 supporters are unrelated to the formulation of strat-
egy and messages. The district court may require the parties to redact the
names of individuals with respect to these sorts of communications, but
the contents of such communications are not privileged under our holding.
   By way of illustration, plaintiffs produced at oral argument a letter from
Bill Tam, one of Proposition 8’s official proponents, urging “friends” to
“really work to pass Prop 8.” A copy of the letter is appended to this opin-
ion. Mr. Tam’s letter is plainly not a private, internal formulation of strat-
egy or message and is thus far afield from the kinds of communications
the First Amendment privilege protects.
604                   PERRY v. SCHWARZENEGGER
reasonably calculated to lead to the discovery of admissible
evidence, but, bearing in mind other sources of information,
they have not shown a sufficient need for the information.
The information plaintiffs seek is attenuated from the issue of
voter intent, while the intrusion on First Amendment interests
is substantial.13

   [19] Accordingly, we grant the petition for a writ of manda-
mus. Proponents have made a prima facie showing of
infringement. Plaintiffs have not shown the requisite need for
the information sought. The district court shall enter a protec-
tive order consistent with this opinion.

  PETITION GRANTED. Each party shall bear its costs on
appeal.




  13
    We do not foreclose the possibility that some of Proponents’ internal
campaign communications may be discoverable. We are not presented
here with a carefully tailored request for the production of highly relevant
information that is unavailable from other sources that do not implicate
First Amendment associational interests. We express no opinion as to
whether any particular request would override the First Amendment inter-
ests at stake.
PERRY v. SCHWARZENEGGER   605
     APPENDIX
