This is illustrative.
What Trump is really selling is an image. A brand. He's the tough-guy, brash billionaire who made his own fortune by being a shark in the business world and now is going to go put those skills to work in Washington as an outsider against a rigged system, no matter how much it hates him. He's a jerk, but he's going to go be a jerk for you, to finally help the forgotten man. If this is what it takes, so be it.
It's an epic tale and he's the hero.
If you want to believe it, you can put your faith in it. He's selling the feeling. It's fun to be a part of the out-crowd, constantly under siege with the like minded, persecuted for what you believe in. What his supporters feel, the image they buy into - THAT is far more important than what he actually does.
Of course it's all bunk. Trump is a liar and a swindler who inherited his wealth from his father and continued growing it with sleazy business practices, lots of questionable and outright failed projects and of course, good old-fashioned ripping people off. The main way he makes his coin - licensing his last name to slap on other people's buildings - is the most laughably lazy way to make money one could think of.
His schtick always requires an enemy, someone to be called out and shamed, someone who is ripping you off or threatening your very way of life. He keeps people continually aggrieved - always focused on Democrats, the deep state, illegals, globalists - so his supporters don't have time to reflect and notice he's not actually fighting for him. He's lining his pockets and setting himself and his wealthy cronies for life after office. He's the one actually ripping them off, so he's got to give them something to be angry at instead. If he keeps 'em occupied long enough he can do whatever he wants, even if it hurts them. It's all about ownin' the libs and feeling like they're winning.
TL;DR: What he actually does isn't as important as the image or brand he's selling for some folks. Good or bad, it is what it is.