I agree with all that feel you cannot throw out a friendship on a single issue. If we do that we will soon the political polarizations of our society ... and that would be sad.
Try and teach your friend, gently, some tolerance. One of my best friends would freak out if he knew of my dressing. I do not know if he would stop speaking to me, but I think it is possible. So, slowly, I am trying to let him see a better way to view differences in people.
C.