The establishment clause is a defense of the city, the state
actor in this case. Basically, if the city allows the religious
expression, it violates Establishment clause by promoting religion.
If it prohibits religious speech, it violates freedom of speech as
a Content based violation. It also restricts religious belief and
so violates Free Exercise Clause. The plaintiffs win based on Free
Speech as the regulation is content-based and the strict scrutiny
standard test is applied and the city's defense of establishment
clause does not meet the heightened scrutiny.