This is a serious answer so it's gonna get down voted to hell, but whatever.
There's a huge portion of Americans who are suffering. Their personal lives are kind of awful, they live in communities that are impossible to get ahead and the communities are often that way to due the direct actions of the political establishment in the late 20th and early 21st centuries.
Above all else, these communities don't really feel heard by the liberal establishment. They feel as though their concerns are dismissed by what they see as the powers that be. They feel that their anguish is belittled as a personal failure, and often downright mocked. They also feel as though a lot of entities that fucked them are liberally coded.
To these people, Trump is the guy who makes those people seethes and tells them to fuck off. That endears them to him and offers extreme loyalty. They often dismiss the allegations against him because at some point every single conservative has been implied to be a disgusting person in popular culture.
Ironically I think a lot of Trump's worst actions solidified the support of his base, because of where America has been at since his political ascendency. The US culture war has been raging for a decade now, and both sides have a habit of taking extreme positions while vilifying their opposition. That is naturally going to cause people to get more aggressive, which in turn villifies Trump.
An example I love to use is vaccine skepticism during covid. There were two huge groups of vaccine skeptics in America: rural whites, and black Americans. Both had suffered greatly at the hands of an aloof medical establishment, and both had their suffering ignored. While the Black community's wounds run deeper, the rural white community was fresh off the opioid crisis. They had every reason to be skeptical about big pharma lying to them for profit, because that's literally what happened just a few years prior.
The liberal response to the black community was understanding and outreach. The medical community made a huge effort to reach out to black community members and popular figures in black culture. There was a direct acknowledgement of the medical establishment's bigotry in the past. There was not a culture of shame for people who did not choose to get vaccinated. This was also reflected in news articles and social media posts.
Their response to the rural white community was basically the opposite. The medical establishment's outreach was extremely limited by comparison. The opioid crisis was written off as a failure by the Sacklers as opposed to any systemic issues that the medical establishment needs to address. Vaccine skeptics were repeatedly and aggressively shamed, with open discussion in regards to simply enforcing vaccination via mandates. Basically every MSM article talked about how the vaccine hesitancy was a character flaw. Social media went even farther. Not only did they call conservative vaccine skeptics things like death cultists, but there were forums dedicated to making fun of antivaxxers dying of covid. People would post private Facebook posts of people they knew by two or three degrees of separation, and then liberals would more or less celebrate their demise. You even had the return of the word "sky fairy" on reddit to describe when these people prayed to God.
Trump, for his part, encouraged people to get vaccinated. He stated multiple times at his rallies that vaccines could end covid, and that they were making him look bad by not doing so. He was, at his own rallies, booed so loud he had to stop talking. He quickly changed his tune.
A consistent trend in liberal circles is the belief that they have complete moral and intellectual authority, as well as the belief that this authority gives them the ability to treat people who don't conform like shit. I'm pretty sure I'm voting for Harris, but there are also times where I felt like I should just say home. It's completely fucking insufferable, and ironically has a ton in common with evangelical christian politics that dominated the US in the 1980s. So long as that mentality is there, you'll have people like Trump gaining undeserved support.