His story was historic. A true political outsider voted in against all odds that went on to get the country's economy in a great place.
He was an asshole, but it was hard to argue with the results...then real adversity struck with Covid and he melted down and he's be self-destructing ever since. Keep in mind that across the world most other political leaders have only gotten more popular in their countries since Covid hit (see NZ prime minister re-elected in a landslide). Adversity typically causes the populace to rally around the incumbent (eg, the historic popularity of wartime presidents). But due to his months long temper tantrum at the end, Trump is instead going to be remembered in the history books as America's wannabe mad king.
Yet some here still support him despite him now trying to take down our democracy and hurt our national security on the way out.