It is early December, 1860, the United States is about to tear itself apart with a full blown war (Civil War/War Between the States). Disregarding the issue of Slavery, explain why you feel that the South should be able to leave the Union constitutionally, or not. Please keep in mind that the South's argument was that the North (New England) had attempted to secede from the Union three (3) times before 1860, but, changed its mind.
And, the fact that the states had bought into the Articles of Confederation which specifically allowed states to leave, if they wished. Also, please keep in mind that from the North's point of view, it is illegal for the South to secede and the Union must be preserved at all costs.