In my circles, mostly for the memes.
In GOP circles, obviously the fact that he was getting millions of dollars from an Ukrainian oil and gas company and a Chinese energy company despite having no expertise in oil, gas, energy, Ukraine, or China, and he's literally on tape threatening Chinese investors by saying his dad would act if they didn't pay him days before they paid him seven million dollars, and other such evidence that he was instrumental in bringing in bribes from foreign nations that were based on gaining access to his father and his power over public policy. Selling access to the highest levels of government? Some people might have problems with the word treason, but it's at very least corruption, and implicates his father as well. A lot less people really care about his drug habit, tax evasion, or gun violations than do that.
Selling access to the presidency of the United States is kinda frowned on in some circles.
Personally, I think just about everyone that gets to that office is corrupt. Maybe not as blatantly, mind numbingly corrupt as Joe Biden/Donald Trump, but the only reason I'm not as pearl clutch-y as Republicans is that I've come to accept such awfulness as common and expected. It's no less awful.