States Establishing Religion

With thanks to the Archpundit for pointing me to this link, in an interview with the SBC Baptist Press, Keyes acknowledged the direction in which a state (or community) established religion could go:

With such a constitutional interpretation, Keyes acknowledged, Catholicism likely would dominate in the Northeast and Protestantism down South. With a growing Muslim population, a state could even have state-sanctioned Islamic symbols and schools."

I don't think it would be likely, but it would be possible," Keyes told Baptist Press.

I guess I'll give Keyes points for consistency, but beyond the academic argument, didn't a little thing called the Taliban illustrate the practical problems with a state-established religion? Is the distinction between a state in the United States different from a country, even if Afghanistan is smaller than Texas?