I get the idea it's like Mark says on the program. The Republican party is the party of WASPy exclusion, and everyone who feels he's a minority has a tendency to believe that he is amongst those hated by Republicans--thus, such a person is "automatically" Democrat for life. I think that's crap, but it's based on solid and repeatable behavior history of the bulk of Republicans. Sucks for someone like Paul, but to look at it from another angle, the gay vote isn't going to be a big problem for him anyway, because he's going to be in the debates he's in, etc., etc., without them.
I hope you're not expecting Ron Paul to win, or anything, and even if he did win, I hope you're not expecting him to be able to change anything. IMO, his value is in his access to the microphone to espouse the ideas of liberty--and he's doing that.