I can't think of a situation where it needs to come up. I have a friend...one of the first people I met when we moved here and I knew absolutely nothing about raising chickens or anything else and would've killed them all if it hadn't been for her (she owns the ONLY feed store I will ever go to here). It's only been in the last year we've talked politics at all. She supports Obama and isn't particualarly wild about the war. OTOH, she adores my son and ALWAYS gives me something from her to include in his care package when I send one. But we have more in common than we disagree about. We share a deep love of animals, country living, gardening, caring for the environment around us, concern about our children. I adore her and can't imagine politics getting in the way of our friendship.
But I live a pretty unique place. The closest town to shop in is Cottage Grove with is sandwiched between the very liberal Eugene and the much more conservative Douglas County (our little grocery store puts out a creche every year for Christmas). There's a feminist bookstore on one corner and the National Guard Headquarters on the other. The bookstore had a huge WELCOME HOME TROOPS when they came home last year. They also had large John Kerry signs in 2004 and Obama signs now. We might have someone collecting money for vets in front of the Walmart and the tie-die crowd protesting on the corner by the natural food store. One car "breaks for fairies" the next gleefully runs them over. Everyone gets along pretty well, conversations can be lively but respectful. It's a pretty great place to be.
Cindie