They are NOT obsessed with slavery. They are obsessed with bringing America down by any means possible.
If they were obsessed with slavery, they would discuss current, ongoing, modern day slavery which is happening right now in Asia, the Middle East, and Africa.
A couple of years ago, an African Black Muslim group called Boko Haram captured hundreds of Black schoolgirls with the declared goal of making them into forced wives or selling them as slaves. But you never hear a word about this in any high school or college in America. Because it does not fit the agenda, White Christian American = bad, all the rest of the World = good.
Dwelling on American slavery from 150 years ago is another means the Left uses to tear America down. Since the Left cannot attack America on merits, they dredge up slavery from centuries ago (which was a normal practice worldwide at the time) to say that America is founded on social injustice. By that measure, there is no people or culture on Earth that is not tainted in one way or another. Even the Native Americans had slaves.
But, never mind with truth, accuracy, or context. That is not the point by far. The goal is to taint America with any age old issue the Left can dig up.
I'm not saying this in any other way except from my heart and my own conscience. It would be so much better for the world if the Left would get off of 200 year old slavery, and focus more on global slavery happening today. That is an issue with which I could join with them, and support them any way I can. However, the Left's relentless focus on slavery from hundreds of years ago, and only in America, obscures the global fight to end modern day slavery happening right now, today.