ACLU vs Allegheny County pretty much answers the religious displays at public buildings question.
Supreme Court case superiority guy.
From a guy who attacks little girls with Festivus Poles? Consider yourself added to my list of grievances.
BTW, your citation form is wrong. The case is
County of Allegheny v. American Civil Liberties Union, Greater Pittsburgh Chapter, 492 U.S. 573, (1989). Holding that, "[a] creche display has that unconstitutional effect, but [we] reverse the Court of Appeals' judgment regarding the menorah display".
Considering that it was a 5-4 decision from 1989, with Kennedy writing for the dissent, I wouldn't push it. It would very likely be overturned if a similar case came up for certiorari.