Remember that they are your family and love them anyway :-). Family is one of the things that "really matters". Even the part that drives you nuts.

Political parties exist to create a kind of blindness, a loyalty over sense kind of blindness. It seems to me it's gotten much worse in the last 2 decades but perhaps I've just better at seeing it as I've aged and learned. Separate the party from the person. It can be painful to watch people you care about, who you know have the "smarts" to do better, parrot things we know to be false because that is the belief they've chosen, because that is the belief the high priest of The Party has dictated to them. For me it helps to remember the "who I care about" ahead of the rest. And then I smile and change the subject ;-).