It would definitely be wrong to fire or sever all ties with someone for supporting, say, George W. Bush. On the other hand, it would be appropriate to do so if

It would definitely be wrong to fire or sever all ties with someone for supporting, say, George W. Bush. On the other hand, it would be appropriate to do so if said person supported Hitler. So the question is where you put Donald Trump on that spectrum. Personally, I think he's much closer to an authoritarian populist than to a regular politician. You may disagree with Trump's placement on that axis, but I find it very strange to see so many people in this thread arguing that punishing someone for their political position is always wrong, no matter how vile or dangerous said political position is.