How do I break up with friends?

So, had wine with some friends and their spouses. Admittedly their political views lean towards the conservative side. We are all entitled to our opinions and I try to maintain respectful, albeit we have had our playful jabs and debates. However, I could not believe my ears when the discussion turned to how Barak Obama needs to just "present his birth certificate" and be done with it. I was so blown away that I thought they were joking. I was shocked and then disgusted when I heard them talk about how he was born in Kenya, is a Russian plant and un-American who doesn't represent the original views of our founding fathers to have a christian nation. When I challenged them, I faced so much wrath and belittlement that I couldn't speak. I was labeled a liberal who needs to be saved. By the way, their husbands is why my husband refuses to have drinks with my girlfriends and their spouses - he finds the men especially toxic. I always thought he just took them too seriously - well, shame on me!

So, I got home, threw up for about 1 hour (I truly did) and told my husband that I just had drinks with the nazi party and was so mortified. I love my girlfriend but her gay-bashing, anti-foreigner, anti-whatever husband can go to hell. I definitely see his conservative ways having influenced her over the years. She used to be so open and accepting - albeit a conservative - but not a blatant racist. As my husband tried to comfort me - he pointed out that she is a big girl and can make up her own mind on things...and she obviously has.

I feel awful. I guess it's because the curtain has been drawn and I can see - really see and hear what is being said. Time to step off the cliff and make some waves as I say goodbye. But it hurts and it's like breaking up...well, it is breaking up. I would never associate with people like this - I guess 10 years of a friendship that never got to this point until this weekend is what makes this so difficult. I want to hold on to the good things that I remember...but I don't see much good developing from this. Friendships are supposed to grow and help one grow. Don't see that happening here.