Republican voters grew tired of wimpy, wimpy, wimpy Republicans. They may have acted like nice guys in white cowboy hats but they refused to fight and accomplished little. Like the Democrats, they looked down on the people who voted for them and considered them to be a bunch of rubes.
Along came Trump who wanted to restore this nation to greatness whIch reminded voters of Reagan. He also was willing to fight. He might have been more of a street fighter than a polished professional politician but at least he was a fighter. Plus Trump‘s first opponent was Hillary Clinton who was a very polarizing candidate. you either live Hillary or hate her.
Trump won.