Shurtleff v. City of Boston, 2022 U.S. LEXIS 2327 (S. Ct. May 2, 2022) (Breyer, J.) When the government encourages diverse expression—say, by creating a forum for debate—the First Amendment prevents it from discriminating against speakers based on their viewpoint. See Rosenberger v. Rector and Visitors of Univ. of Va., 515 U. S. 819, 828- 830, 115 S. Ct. 2510, 132 L. Ed. 2d 700 (1995). But when the government speaks for itself, the First Amendment does not demand airtime for all views. After all, the government must be able to “promote a program” or “espouse a policy” in order to function. Walker v. Texas Div., Sons of Confederate Veterans, Inc., 576 U. S. 200, 208, 135 S. Ct. 2239, 192 L. Ed. 2d 274 (2015). The line between a forum for private expression and the government’s own speech is important, but not always clear. This case concerns a flagpole outside Boston City Hall. For years, Boston has allowed private groups to request use of the flagpole to raise flags of their choosing. As part of this program, Boston approved hundreds of requests to raise dozens of different flags. The city did not deny a single request to raise a flag until, in 2017, Harold Shurtleff, the director of a group called Camp Constitution, asked to fly a Christian flag. Boston refused. At that time, Boston admits, it had no written policy limiting use of the flagpole based on the content of a flag. The parties dispute whether, on these facts, Boston reserved the pole to fly flags that communicate governmental messages, or instead opened the flagpole for citizens to express their own views. If the former, Boston is free to choose the flags it flies without the constraints of the First Amendment’s Free Speech Clause. If the latter, the Free Speech Clause prevents Boston from refusing a flag based on its viewpoint. We conclude that, on balance, Boston did not make the raising and flying of private groups’ flags a form of government speech. That means, in turn, that Boston’s refusal to let Shurtleff and Camp Constitution raise their flag based on its religious viewpoint “abridg[ed]” their “freedom of speech.” U. S. Const., Amdt. I.