You do your best to never talk about it! Myself and my husband are complete opposites both religiously and politically from my in laws. Out of respect for them I never discuss it. When they bring politics up I remind them that there is no chance we will ever agree so the polite thing to do is drop it! If that didn't work then I would assume they lacked respect and likely distance myself. If someone can't respect my views enough to let it go when asked then I have no reason to continue contact.
It might seem like an over reaction, but family should have a sense of respect for each other. When that respect isn't there, why waste time trying?