"The slave owners eventually became the modern Democratic Party"
No they didn't
"Black Americans vote 90% democrat although that is changing as they realize they are voting for the people that hate them"
Democrats don't hate black people
"If they they disagree with the party line, they are humiliated, threatened, punished"
That's true for both sides. Look how a lot of conservatives react when you say Trump was a bad president, or the 2020 election wasn't rigged.