My theory is that Trump supporters are spurred to like him for any of these reasons: 1) Backlash to political correctness/alt right. These people are young and do not care about policy, jobs or issues in general they just hate the left and academia. 2) Old people who live in hick towns who want blue-collar jobs to pay for their mortgage like they used to. (These jobs are either gone forever to automation or to China) Newsflash your jobs are not coming back. They ruined the planet anyway with all that coal. 3) Lifelong republicans who supported Trump only because he was Republican. This includes people who vote single-issue like pro-life. 4) People who hate Clinton and would vote for anyone else, at all.

3 & 4 have some overlap.