[rootusrootus]

Turn the other cheek. Steer the conversation back towards something less contentious. If necessary, confront them... but not as a partisan. Challenge them to abstain from political discussion in favor of a happier conversation. If they really cannot be adult enough to make that choice, then it really isn't politics that is the problem, it's just a symptom.

[emodendroket]

At a certain point you're just tired of that and want to excuse yourself and go home.