Their policies are, though. So you take a given Republican who is not personally anti-gay but nonetheless votes for someone who votes for DOMA. The actions of this person are anti-gay – perhaps indirectly but nonetheless the person took a deliberate action (voting) in full knowledge of the consequences (support for DOMA).
This is the problem with rigid Aristotelian syllogistic logic. The words we actually use in real-life examples and the ways in which we use them only rarely hew very closely to categories that are strictly Aristotelian. While you can certainly argue that the existence of a pro-gay Republican somewhere invalidates any and all arguments to the effect that the Republican party is anti-gay because “a single counterexample disproves blah blah” we come back to the real world where ostensibly non-anti-gay Republicans support candidates who are indeed anti-gay – or at least act the part because so much of their constituency is anti-gay.
And if I want to use the term “anti-gay” to refer to people who support organizations that take actions that can reasonably be construed as “anti-gay” you can disagree. At that point it’s a purely semantic distinction with no real moral dimension except, perhaps, that it makes you feel bad when someone says Republicans are anti-gay by a pretty reasonable definition of “anti-gay”.
As far as your first example goes, you do realize there is more than one Christian church and some disagreement between them as far as what is required for salvation. You might also realize that plenty of people consider themselves “cultural Christians” without actually believing in the divinity of Jesus Christ. Once again, trying to use Aristotelian logic to describe the universe leaves your models with holes. (Not even getting into how much it drives me up the wall when people make absolutist statements about the interpretation of the gospels.)
