The US Supreme Court frequently takes up cases involving the Establishment Clause about the extent to which religious elements can be introduced into the public sphere. Rather than unequivocally declare that it should never be allowed and thus ending the debate once and for all, a decision that would likely result in them having to face the wrath of the religious in America, they have instead tried to rule very narrowly, inserting intricate conditions on when such things can be allowed. They have done this with prayers, religious displays, and the like.
The aftermath of such rulings has also been predictable. Religious people ignore all the conditions that the court laid down and proceed to act as if they were given carte blanche to do whatever they want, triggering a new round legal challenges.
This has happened with the so-called ceremonial prayer to open meetings of government entities. In the case Greece v. Galloway, the court ruled that such invocations were acceptable as long as they were non-sectarian and open to all faiths and non-faiths. But the Ohio Senate has decided that secular, non-religious invocations will not be allowed and that they must “be given by an ordained representative of that faith, it must appeal to a higher power, and the individual must be sponsored by a member of the Legislature.” The Freedom From Religion Foundation has now issued a legal warning to the Senate that this practice is unconstitutional.
Then we had the Masterpiece cake case where a baker was allowed to not bake a cake for a same-sex wedding. The court said that this decision was narrow and that the more general issue had to await a later case. But the owner of a hardware store in Tennessee decided that it was a blanket license to discriminate and put up a ‘No Gays Allowed’ sign on his store. That will undoubtedly be challenged too.
As long as the Supreme Court continues trying to not offend the religious by issuing intricate rulings, such cases are going to repeat themselves over and over.