No. The people are supposed to be sovereign.
The Constitution exists because the Articles of Confederation, which set up a voluntary association of sovereign states, wasn't a sufficient basis for a new and growing nation. There was a consensus in favor of a stronger central government, though some Founders -- most notably Samuel Adams and Patrick Henry -- differed strongly and in no uncertain terms.
The balance of powers between the Feds and the states was a struggle from the beginning of the Republic, as was the question of whether a state that had joined could later opt out -- the latter wouldn't be answered until 1865, and then only by force.
"That whenever any Form of Government becomes destructive of these ends, it is the Right of the People to alter or to abolish it, and to institute new Government, laying its foundation on such principles and organizing its powers in such form, as to them shall seem most likely to effect their Safety and Happiness."
And so is the federal government.
And so are the people.
Just because one thing is sovereign, doesn't translate into only that one thing being sovereign (except for God, who is de facto the the only being who is completely and fully sovereign).
Which arguably is not a constitutionally sanctioned answer.
The balance of powers between the Feds and the states was a struggle from the beginning of the Republic, as was the question of whether a state that had joined could later opt out -- the latter wouldn't be answered until 1865, and then only by force.
The fact that the states were kept from leaving by force doesn't answer the question. Any sovereignty the states had before entering the Union was retained except what was written in the US Constitution. The right to leave was not given up and so the actions of the ferderal government to keep them from leaving was illegal.
For libs, this will not be a problem, given how quickly those Dems who voted for going to war in Iraq have found reasons recently to say they really would have voted against it.
They probably have not thought this present passion all the way through. They don't realize what a can of nested hornets they will be opening up if they push this further.