I really don't think that for anything you can clearly say "all believe this or that". I think this situation is a more clear "no" answer, but it is bad to say that an entire group believes or agrees with something, even if there is evidence that they do. This situation is the opposite where you have groups that are gay and support republican candidates because of their fiscal and foreign plans.
There are many hundreds of thousands of Republicans in the United States.
How could it be possible that all of them are homophobic?
I'm pretty sure that some of them are homosexuals as well, honestly.
By the way, Republican does not automatically equal homophobia. That has more to do with the religious ideologies of most Republicans than it has to do with their political and economical stance.
I know a conservative who is not hateful. She is a sweetie. She is one of the few people Who treats me like a human being. Based on her pattern of conduct, my answer has to be no, not all of them. Just some of them. Word up yo. Random word filler here.