So far as I know, everyone posting here to defend the Union side of Civil War also agrees that secession could have been, and still is, lawful & constitutional, provided it's done in accordance with our Founders' original intentions: 1) by mutual consent -- meaning with the approval of Congress, or 2) as a result of usurpations and oppression, which I would say should be confirmed by the Supreme Court.
Yes, those are very high bars to clear, and any state combinations which could jump such hurdles would doubtless also have the political wherewithal to effect necessary changes within the Union.
But there it is.
“would doubtless also have the political wherewithal to effect necessary changes within the Union.
But there it is.”
Sometimes it seems that congress just marches on, continually defying the consent of the governed. And SCOTUS...well just look at 0bamacare rulings recently.