I have to say, Trumps last comment is strange.
Why would he say "Proud Boys, stand back and stand by...."?
This has been overly scrutinized by leftists trying find a gotcha on Trump.
He's not saying anything different than conservatives have been saying for months now.
Citizens enter into covenants with their government.
One of which is that the government will through taxes keep people safe (police, national guard, etc.) so that citizens don't feel the need to constantly defend their life, liberty and property as if it was the wild west.
When that breaks down, when the covenant is broken, a citizen has two choices. Be a victim, or defend your life, liberty and property.
So when the government lets rioting and looting persist without honoring its end of the covenant...as Trump said at the end of that quote, eventually somebody has to do something.
It seems to be more a point about the left wanting people to just bend over and take it, which is anathema to the purpose of government.
In other words, Trump is endorsing defending yourself (and each other, which is an important point), as he should.