Read Jefferson's and the Founders ideas of State's rights. You know ... small limited government with primary right of self-determination belonging to the States?! AND the right to seceed if they didn't feel the government was acting on their behalf! After all, that's what representative government is all about. Representative is the key word here boyo!
Once again, if the issue where anything OTHER than SLAVERY, you'd have a case. If the south had severed its ties to the federal government due to shipping lanes, or water rights, or anything other than slavery, the argument of states rights would be be arguable. The fact that the southern states rode the wrong horse (slavery), doomed their argument. And it makes apologists for the Confederacy today look ridiculous. Argue your point, but don't try to refight the Civil War.