what would you do, were you a Democratic President?
The poll is below the fold.
My own opinion: Option 4- I would simply let them go and get on with business.
Why is the situation different than 150 years ago? My answer is that slavery is "worse" than, say, the infringement on the rights of other minority constituencies that would ensue in the New Confederacy. We're also much more mobile as a society. It's not clear to me in which direction net migration would be, although I suppose it would be northward, and the attendant costs of moving would represent a damage to Americans we would be "abandoning." So, I think I see arguments on both sides.
But, in the end, I am also a realist, and the rampant fascism characterizing the New Confederacy enjoys tremendous popular support there, and against such support it is difficult for the Courts to fight the persistent battle they must to preserve the rights of the minorities.