Where exactly did Trump fuck up as president?
Well, imo the way he went about the wall idea was kinda stupid. I am all for ramping up border security to the extent I'd support motions to load border crossers into catapults and launch them back over. But he got very stupid with the idea and let's be honest, the mexicans figured out how to dig tunnels and shit a long time ago. By the time he adopted a more sensible approach of working with the Mexican government and levying trade against them to have
them effectively be the wall and send the central american migrants back it was too late and he already looked like an idiot.
For a man who even had a TV show about hiring the right people for the job, a lot of the people he insulated himself with were treacherous pieces of shit who undermined him at every turn, got themselves fucked up in trouble, and then turned on him and anyone else the Dems wanted them to. This can probably mostly be blamed on him stupidly letting Kushner be a part of any of it whatsoever, I guess to shut his mewling brat up, but it still ended up torching him.
And last but not least, he had four fucking years to recognize the threat that the Democrats were building up with their fraud and scheming, and he barely did anything about it until the 11th hour when their mechanisms had already been securely in place and their operatives spread far and wide. It's especially glaring when you realize that he did actually have a relatively easy intro to his term compared to what would come after.
tl;dr his main fuckup was either doing things or ignoring things that would eventually result in Dems being able to bribe, lie, con and fraud their way into absolute power once more. We didn't just lose the presidency we also lost the fucking Senate and now everything is on the table. Beyond that I definitely liked him better than Biden, he posed a significantly lower risk to our freedoms, the economy was actually doing great pre-kungflu, and he made significant strides in improving relations with some of the countries that could actually pose a significant risk while also pulling us out of sandy Vietnam. Under Trump it felt like we actually knew who we were and were finally willing to tell Europe to eat a bag of dicks with their globohomo agenda. And tbh I think his crowning moment in my eyes was the recognition that the space race is far from over and that we as a nation and hell, as a species, need to seriously start expanding our borders past the atmosphere and into space. People mocked him so much for the "Space Force" shit without even realizing that without it we are going to end up sitting on this decaying rock while countries like China zoom into space and start claiming shit like it's monopoly.
Edit - Another thing I really liked about Trump - He was brash, arrogant and acted retarded sometimes, but goddamn did that man exude American pride. He actually seemed to, ya know, like our country.