Except the Southern States still will part of a Rrpublican government with the consent of the governed. In fact they controlled the Supreme Court. Just like Gore vs Bush, Democrats wanted to suppress the consent if the governed and play by their own rules.
The Government no longer had the consent of the Southern States, just as England no longer had the consent of the 13 slave owning colonies.
What the rest of England thought was immaterial. The Founders obviously regarded the right of states to secede from England as valid.