If he was like Peter Bell or Hughento, yes. But not if he was just basing his campaign on “I’m gay, so elect me!” or making it a big deal throughout the entire campaign. I just wouldn’t vote for him if he was trying to use being gay to win the election, otherwise I wouldn’t really care.
Basically what CheeseWhiz said. I generally dislike people who insist on serving up their "oppressed minority status" on a silver platter to get sympathy from the masses instead of having an actual agenda, a solid campaign, et cetera. It's all right if the candidate is openly gay and doesn't constantly demand pity and attention from voters because s/he is a "minority"; taking advantage of and abusing that "oppressed minority status" to gain sympathy instead of gaining attention through sheer competence is simply not something that I respect. I don't care if the person is homosexual, Black, Hispanic, female, old, young, wheelchaired, poor, transsexual, and so forth, as long as s/he is qualified and competent. But if the person thinks that using the "oppressed minority status" is a viable substitute for competence, then that's when I would have a problem.
Just replace "gay" with "bisexual".