I'm gay and the GOP is the anti-gay party. They have opposition to gay marriage and domestic partnerships as a plank on their national platform, and individual Republicans have consistently opposed civil rights protections for the GLBT community, among other things (though individual Democrats have done this too, here in Dayton).
I know there is that Uncle Toms Log Cabing Club or something for gay Republicans, but it doesn't seem to have much effect on the party.
So that is your answer: the GOP is my political enemy, so I don't support them.
I love how liberals can get away with saying that the GOP is "anti-gay" or "the white party" without an outcry. If someone said something as ridiculous about the Democrats like they are the un-American party or the pro-Victim party, we wouldn't hear the end of it. Inspiring desperation into the public discourse is the MO of the Democratic party. But they only peddle despair because they have the magic panacea: more government in your lives!
To say the GOP is the anti-gay party seems to be an overly simple line of attack. The argument is quickly reduced to two camps: one is crying that every identity group deserves its own civil rights protection amendment and the other believes government ought to provide equal protection under law regardless of one's group affiliation. If you are part of the first camp, where do the protection amendments end? I am asexual and wish to share domestic partnership benefits with my best friend. Do you condone my effort to live the life of my choosing (or was I born this way) or do you oppose my efforts and therefore become my political enemy?