Originally Posted by AvengerRam
I'll take your hypothetical one step further. Let's assume that in the school district in question, 100% of the population is of the same sect of the same religion, and there is no chance of that ever changing.
Its still unlawul to require prayer in public schools.
This is where the 14th Amendment comes into play. While the First Amendment prohibited acts of Congress, the 14th extends protections and prohibitions to the States. In doing so, the 14th Amendment reflects a policy of not allowing States (or, by extension, counties and muicipalities) to have unlimited freedom to opt-out of the base principles of the Constitution by virtue of local legislation.
Just as a muncipality cannot pass a law that states, "In the Town of Bohunk, it shall be a felony to express opposition to the government," (even if everyone in the town thinks that's a good idea), a municipality cannot sponsor prayer in public schools, regardless of the majority's will.