[KurtFF8]

To refresh your memory, Texas v. White was the Supreme Court decision that ruled that secession was unconstitutional on the basis of "to form a more perfect union".

But a quick counter argument could be that the south remaining a part of the Union would have made the Union go through more trouble and be more divided, so secession made the Union more unified as well as the South more unified, therefore secession being to help the Union be "more perfect".

It may sound like some of a stretch, but I'm sure more would have to be looked into, like how much the South leaving really hurt the economy, etc. because of course the political atmosphere at the time didn't allow for a true neutral view of the case.