I think people would rather erase history and suppress freedom of speech for fear of offending someone.
And that's what this is truly about. As for the "state's rights", it was more about the individual rights of those who lived in the south. Those states felt their residents had the right to own slaves as property.
Are some of our snowflake states any different these days? I see the folks in California and a few other states refusing to support the President in his goal to tighten immigration.
So when you look at it, we've always be a "United States" in name only. People in Texas want unrestricted gun rights. People in some states want no part of a federal minimum wage.
The only thing missing is the declaration to withdraw from the "United States" as was done in 1861. Slavery was an abomination by today's beliefs and standards but certainly not by those in the 1800's. There were thousands of slaves in the north back then too.