We have a lot of, umm, error in the United States going on right now when it comes to major media. And many "fact checkers" being pretty shit.
Much of the capitalist press is overtly critical of Trump, but usually in ways that don't or shouldn't matter to anyone who doesn't own lots of shares in munitions companies or, which is perhaps even worse, just empty xenophobic innuendo gesturing at supposed treason. At the same time, the major media often likes to promote a 'both sides' narrative whenever anything a Republican does is bad or silly. That includes Trump.
https://fair.org/home/both-sides-ing-bleach-injection/
So it's pretty easy for a narrative that "Trump is actually honest, it's just everyone else who lies" to take hold among people predisposed to that view because the loudest voices in the capitalist press really do suck at their purported jobs.