"Why should those states leaving be able to walk away from it?"
Paying a debt is one thing.
It was owed.
Seceeding is another. It is based upon the idea that the states all joined in a contract.
When the contract was broken (in their eyes) then they had no reason to stay. (And the Union had no reason to keep them)
But by saying that the states could unilaterally walk away from the Union at will you are saying that they could also walk away from their obligations at will. What was to stop them?
Seceeding is another. It is based upon the idea that the states all joined in a contract. When the contract was broken (in their eyes) then they had no reason to stay. (And the Union had no reason to keep them)
The contract was broken merely because they said it was? Why is their side automatically the right one? What if the other parties in the contract didn't think it was broken?
And if you insist that the Constitution was a mere contract, then what contract allows only one side to break it?