The Trump fan base is composed of people who are fed up being scolded by elites because of values that do not conform to liberal political correctness. Look through any newspaper from two or three years ago. The amount of name-calling and bullying was intolerable. Against abortion? You're a bigot and misogynist. Concerns about immigration? You're a bigot and xenophobic. Favour traditional family values? You're a bigot and homophobic. 

These positions can easily be debated without the name calling and bullying, but it was easier to keep opponents silent by calling them names.  People eventually tumbled to the fact that they were being ruled by small determined groups of people with agendas, and the backlash started.

Trump is a horrible man and the worst president ever, but he makes his fan base feel that their views count. Liberals have to learn that they can't win over people by making them feel like PsOS.