American here.

Because Americans are stupid.

Well, enough are anyway.

This is the country that made a convicted felon and adjudicated rapist with one failed presidency under his belt our leader...again.

We did already impeach him...twice. But now Republicans are in total control (see stupid Americans comment above), so Republicans would have to impeach him this time, but they're all spineless fascists, so that isn't happening. In America impeachment is just the first step, then the Senate has to actually remove them. After the first two impeachments the spineless fascist Republicans in the Senate refused to remove him, even though it was at the very end of his first term and gave them the perfect opportunity to permanently rid themselves of him. But again, they are spineless fascists.

Why do many Americans support him? It's a combination of stupidity, ignorance, hate, and fear. Humans who don't receive a proper education or upbringing end up being easily manipulated by those things. That's the case here in America. Expect it to get a whole lot worse.