Trumpeons and their GOP representation warn of the fear of socialism. Yet America became a corporate socialism. A few giant billionaires own most or all of the national retail chains, from hardware and fast food, to department stores, insurance companies, health care, sporting goods, supermarkets... you name it. Competition is dead, and a healthy capitalism depends on competition. In its place we live in a corporate socialism where everything we buy is dictated in a "what we have is all you get" policy, at their prices, under their terms. You can't barter Peter against Paul because a John owns them both. The Koch brothers, Soros, Buffett, the Waltons, Bezos et al are the drivers, and the GOP is a moth in the grill shouting, "Whee! Look at us go!"
What must a person lack to believe Trump? Truth.
Trumpeons like to say Obama lied, and hurt America. Evidence however says otherwise. Trumpeons like to say Trump is truthful, and a great president. Again, evidence says otherwise.
Trumpeons argue millions of citizens support Trump. Many, many millions more don't. Willingness of a few million to tolerate lies from a liar is not sufficient cause to retain a liar as president.
Trump's base is in school about the danger of lies. Long ago the US Military learned those lessons, which led to the Honor Code at all US Military Academies:
"I will not lie, steal, or cheat, nor tolerate anyone who does."
Lies and lying kill. Every time Trump lies, he murders some part of America, including his base.