Trump's flaws are a feature, not a bug. Liberals felt similarly about Bill Clinton -- Clinton was a relatable shmuck who needed us, and that need made us feel passionately defensive of him in the face of the fact that he committed a serious crime, perjury.
Trump shouldn't make it in Washington -- Washington thinks it's better than him, and sneers at Trump supporters. It's only because of the fierceness of their adulation that his career survives. His supporters aren't listing their values and finding that he aligns best with them; they're being unlikely heroes, and making an unlikely hero succeed. When Luke Skywalker is douchey, Star Wars lovers don't cringe and regret their support for him -- his doucheyness is why he needs our faith, and what makes his coming through glorious. That glory simply doesn't exist with, say, Marco Rubio or John Kasich.
To be clear, I think Donald Trump is probably the single worst human being in the United States, and it's a testament to the corruption of the justice system that he has never spent time in jail for his innumerable crimes. I think it's likely he literally committed a crime every day of his adult career.