Because Trump was a far better choice than the alternative offered. Aside from Trump pretty much all the politicians on both sides want to keep commoners out of government. It is like a private club and they only pretend to be different to baffle the low information voters.
See, I really don't understand how you don't see that Trump has been an elitist all his life. Born with a golden spoon in his mouth, sent to the best private schools. He rejected his father's business of building homes for the middle class, selling that off and instead chose to build homes for the wealthy. He started up an airliner just for rich people (which failed) and then built casinos at enormous cost for rich people( and they failed). He runs golf courses for the rich people, drives around in limos and brags about his wealth and somehow you guys seem to think he's one of you? LOL. The only commoners at his clubs at the illegal aliens working there for dirt cheap wages. And he made it clear during his time in office that the only people he respected were rich ones, mocking politicians, including his own appointees, if they weren't wealthy enough.