Before you do anything rash, I disagree very STRONGLY with those who've said you have to get a new girlfriend. You MIGHT have to, but my fiance was much the same way last year and has now been strongly pro-rights for quite awhile. Of course, it helps that she thinks shooting .22's is fun. But it IS possible for such a woman to change her stripes when she's shown the truth. Just don't try to force it and don't let her pretend for your sake.
Good luck.
Good luck.