It depends on the political circumstances.

If several equally qualified candidates are seeking the endorsement of my party (or if it is a primary election), I might well consider sexual morality as one of the factors in deciding which candidate to support.

If the candidate for my party has already been chosen, and the only alternative is to vote for the other party, I would probably stick to my party.

In other words, a Democrat would have to be pure scum to sink below the level of a typical Republican in my estimation. It's hard to think of one who has. Rod Blagojevich maybe?

And I live in a state where politics is pretty clean, so that's not likely to be an issue.