"How can you be gay and be in the Republican Party?"
indeed. almost as bad as the "gay christians" :-(
The same reasoning is that blacks should be Democrats. It's stereotyping to conclude that gays should be Democrats. Why should gays be Democrats, because Republicans tend to oppose homosexual marriage, and Democrats all favor courts re-defining marriage, if not willing to say they support gay marriage outright?
If the Republican party is not exclusively "Christian", nor should it ever hope to be, and if all Christians are not exclusively Republican, and all "conservatives" are not exclusively Christian, but most active conservatives (whether social conservatives, small-government conservatives, Libertarian conservatives, strong-national-defense conservatives, even "atheist" conservatives) are Republicans (I said most, not all), then there is nothing oxymoronic about a "gay" Republican.