HANOVER, N.H. — They think Donald Trump’s ideas are “disgusting.” They think he is making a mockery of the American political system and that even he doesn’t take his own candidacy seriously. And that is exactly why they say they plan to vote for him. Meet Trump’s protest voters. People who in the past might have gone to the polls only to register their disdain for politicians by writing in “Mickey Mouse” — or perhaps even “Donald Trump” — now have a Republican frontrunner to rally around. Like many sincere Trump supporters, they believe the system is totally screwed up....