I actually had to read a study on the "Tearoom Trade" in a criminal justice class. I don't think its a liberal/religion thing. Its being in the closet in general. This is not sexual repression, but expression. If sexual repression caused a behavior, it would manifest itself as something nonsexual. This shit happens w/ liberals too.
http://en.wikipedia.org/wiki/Gerry_Studds
http://en.wikipedia.org/wiki/Oaten