Pleasant Grove v. Summum is about the fight of Summum, a modern religion, to have a monument of its Seven Aphorisms placed in a public park, along with more than a dozen other public monuments there, including a depiction of the 10 Commandments. Although Summum won on appeal, the Supremes unanimously shot them down.
Although I can see how easy it would be to abuse the system if they had ruled the other way -- just about anyone could 'force' the government to express his private opinion on public property -- I still find myself a little dissatisfied.
A government entity “is entitled to say what it wishes,” ... and to select the views that it wants to express, see, e.g., Rust v. Sullivan, 500 U. S. 173, 194. It may exercise this same freedom when it receives private assistance for the purpose of delivering a government-controlled message. ... This does not mean that there are no restraints on government speech. For example, government speech must comport with the Establishment Clause.
So the government is entitled to say this and NOT that. Pleasant Grove doesn't want to say the Seven Aphorisms. But it does want to say the Ten Commandments. But it also must comport with the Establishment Clause...
A city engages in expressive conduct by accepting and displaying a privately donated monument, but it does not necessarily endorse the specific meaning that any particular donor sees in the monument.
So while the monument literally reads "Thou shalt have no other gods before me," that's not what the government is saying. The government only 'said' giant-carved-block-of-stone-is-allowed-h
I just see a little switcheroo going on. When the monument is being approved, the government evaluates the message and decides whether or not it wishes to say it. But then after the monument is approved, the government no longer endorses the message it explicitly approved.
I suppose it's all of a piece with ceremonial deism. When the court is opened with the words "God save the United States and this honorable Court," nobody really means it. It is just a meaningless formula.