Wealthy people who could be coined liberal-tarians or just your average tech bro political grab bag largely backed Trump out of financial interest and who, imo, deluded themselves that the administration would be unsuccessful at "the bad stuff" much like his 2016 run.
No amount of shouting from the rooftops that this time was actually different convinced anyone. I can't really blame us collectively, we resoundingly voted for this— it's as much of a mandate you're likely to ever get in the US and we're in the find out stage of fucking around.
Looking back on old social media posts the theme is that everyone, supporters and not, were high on copium that Trump would do <list of things I like | aren't so bad> and the <list of truly terrible things> was just obviously crazy and wouldn't actually happen or were a joke.