People don't understand why Trump is doing so well. The Rep establishment thinks it's because people are fooled by him and don't understand that he's not a real republican or conservative. Liberals think it is because racism or whatever ism is trending that day. Liberals are wrong on everything so their misunderstanding is expected.
The simple truth of Trump's popularity is that he's a winner. Most Americans, even those why voted for the current clown, do not like the direction we are headed. It has gone too far too fast, with total disregard for law. This is why Republicans won control of congress.
People want to stop the hard move to the left. They put their faith in weak leaders like McCain, Romney, Boehner, and Paul Ryan who just roll over and let the liberals get away with whatever they want.
So now the people want a guy who has a backbone. They want somebody who will fight and win. Primaries are usually about people being picky about getting a particular candidate for their main issue. Evangelicals have their guy. People worried about the economy have their guy, etc. What usually happens is all the groups divide the vote and a weak middle of the road guy like Romney slips through.
This year is different. This year you have Trump winning with groups he should have no chance with, like Evangelicals. The reason is people inherently know that the country is ****** if a Dem wins and continues taking us off a cliff. This means people have quickly identified the guy they think can actually WIN even is he doesn't check all the boxes they want on various policies.
Trump will be strong on the economy. He will stop the immigration anarchy, and he act in America's best interest, not the United Nations best interest on foreign matters.
That's why Trump is winning, because he's strong and people are sick of weak opposition to the liberals.