Instead of allowing states to secede - an admittedly absurd notion - instead, allow those who call for secession to voluntarily leave the country they apparently despise so much, be stripped of their citizenship of the country they can't stand to be a part of, and find a new home elsewhere.
This is the land of the free and home of the brave. That means that we are brave enough to stay and fight (peacefully and diplomatically) for our country if we believe it is leading us down the wrong path. If an individual is so tormented by the current state of the union, that they cannot put forth the effort to improve the country that they once claimed they loved so much, then they should have every right to leave, and no longer be considered part of this nation. However, all lands should remain.