In those public fora cases, the state—as it has here—will interpose as a compelling state interest the need to avoid a violation of the Establishment Clause and will argue that permitting the religious speech may send a constitutionally impermissible message of state endorsement. This might be true if the private party communicated the religious speech on government property that was not a
true public forum. Precisely because the religious speech is communicated in a true public forum, however, the state, by definition, neither endorses nor disapproves of the speech. By permitting religious speech in a public forum—whether in the heart of a core government building, in the Georgia Governor's mansion, or in the outer reaches of some state-owned pasture—the state simply does not endorse, but rather acts in a strictly neutral manner toward, private speech.
See Kreisner, 988 F.2d at 895 (“The public forum doctrine would be rendered meaningless if only places in the middle of nowhere could be free speech areas, and if all speech that occurred near ‘structural symbols of government’ had to be viewed as government speech.”);
id. at 894 (“In any event, even the proximity of buildings of unmistakably governmental character is a patently imperfect proxy for attributing speech that goes on there to the government.”);
Doe, 964 F.2d at 630 (Easterbrook, J., concurring) (“That a public forum may be close to city hall cannot matter; any forum open to secular speech must be open to religious speech.”).
The whereabouts of public fora matter only to the extent that satisfaction of the state's burden of familiarizing the public with the nature of public fora (and the state's corresponding neutrality) may vary in difficulty. The public may be less inclined to attribute private speech to the government when the speech is communicated in a public park rather than, as here, in a core government building.