And I understand that. Where I live my political beliefs are far more conservative than my neighbors so I don't go out and talk about it either, for the same reasons you gave.
But if I'm called by someone taking a political poll I don't mind answering honestly because it's entirely different circumstances. Nobody else knows, so nobody will try and make a major argument of it. I'll tell them I'm voting for the Conservative candidate even though I live among a sea of red and orange. I went and voted for the Conservative candidate even though I knew the Liberal was going to win. Why should Trump supporters be different?