I've unfriended people for experiencing far right beliefs... Not real friends though; just Facebook friends. I already know my real fiends political alignments, but being my friends none are extreme far right, and I don't mind some political disagreements.
That said, Trump is pretty extreme and unpleasant. I'm not American but if I had a friend who through trump should be president... Well at first I'd assume they're joking... Then I'd try and reason with them... Then I'd unfriend them.
I don't need people in my life who are OK with, or have somehow rationalised, his bigotry and comments claiming to commit sexual assault.
I understand many of his supporters aren't truly extremists and are just looking for someone who isn't the status quo, and you could have a debate about whether he really is offering real change (I suspect he'll pretty much be like any other republican once in office), but if people can turn a blind eye to all the extremist stuff Trump's said then it does say something about their character.