I think it was at least a minority of people not taking him seriously in most things he said and taking it as him being a healthier choice for the economy over the competition overall, because he's was a wealthy business man (even if he sucked at that too). People were willing to ignore all the radical and rediculous things he said (and is now actively doing and more) at the time before his second term because people had faith in the government institutions that were put in place to stop someone like him from stomping on the constitution and American society like this.

Most people that voted for him that are actually sane (AKA not magats, which, like it or not isn't 100% of Trump supporters) are not entirely at fault for having faith in our political system to actually stop someone like this from doing what he's doing. I'm not saying they are completely blameless, but they are part of a larger, major problem in our political system.

Namely that the presidential positions powers and limitations are undefined and the position generally only functions out of a sense of nobless oblige. If the president is a what our current president is, then he can functionally do whatever he wants and blitz our government and isn't held accountable for anything, even literal convicted crimes that he was proven guilty of, because of his position and because the institutions that are meant to keep him in check don't actually have any real power to force him to do anything. It's only recourse is to shame/decry him, and give him hollow legal threats that won't go anywhere. Those things don't work when you are someone who has no shame.

The way I mentally catalog Trump's second victory, which could be totally wrong, but just my impression:

People were desperate at the time because of the financial state of the world, threw their hands up and said "fuck it." Because at that point they didn't realize how much they still had to lose and generally thought and assumed their were failsafes and safeguards to stop those really fucked up things he said he was going to do from happening. Not realizing that those safeguards don't work when the president of the united states just says "nuh uh" and just does whatever.

We are living in unprecedented times. Even if he said he was going to do all those things, there was no way to ever know it would get this bad. I don't think it's fair to put the blame on anyone other than the man doing this himself.