The subject of modern slavery probably can't be approached here. The third rail for the right is slavery while there is still a lust for slavery among the extremists. They want it but have to a go at it obliquely with nullification, institutionalized racism and private prison labor.
Slavery is still an existential global problem!
At any given time in 2016, an estimated 40.3 million people are in modern slavery, including 24.9 million in forced labour and 15.4 million in forced marriage.
It means there are 5.4 victims of modern slavery for every 1,000 people in the world.
1 in 4 victims of modern slavery are children.
Out of the 24.9 million people trapped in forced labour, 16 million people are exploited in the private sector such as domestic work, construction or agriculture; 4.8 million persons in forced sexual exploitation, and 4 million persons in forced labour imposed by state authorities.
Women and girls are disproportionately affected by forced labour, accounting for 99% of victims in the commercial sex industry, and 58% in other sectors.
Source: Global Estimates of Modern Slavery: Forced Labour and Forced Marriage , Geneva, September 2017.

With recent Supream Court decisions states rights could include a form of elective slavery just short of purchased ownership of people in states like Mississippi or Texas that could bypass the judiciary. This may not be as hypothetical as you think. Republican think tanks 'dare to dream'.
It does depend on how you define Democracy.