[RobbyS]

The Supremacy Clause saves nothing about the right of secession. You assume that the Constitution gave the central government the powers that Lincoln claimed it had. Lincoln even violated a recognized tenant of both municipal and international law which was to blockade the ports of his own country. The salient term before the war was "Union", not nation. Sovereignty such as it was lay in the Union, not in the central government, which did not by design have a military large enough to suppress the southern rebellion without calling upon the northern states. Jackson had by such means brought South Carolina to heel by such means, but they were useless against such a large combination of the elites of so many states.

Since Washington's administration a compact theory of the Union, which emphasized the voluntary nature of the Union, had many supporters. even New England was willing to invoke it during the War of 1812. Webster, who so eloquently articulated the idea of a permanent union in 1831, had had quite a different view tin 1813. Lincoln, like Webster a Whig, simply adopted Webster's theory of the Union. in opposition to the Jeffersonian- Calhoun view. Since his side won, that settled the matter, although the lawyers were able to cover up the cracks in the original constitution by means of the 13th and 14th Amendments. Stylistically, the change in view of the country was reflected in the pre-war references that the United States "are," as opposed to 'is" after the war.

[x]

The Constitution apportions powers between the federal and state governments, but the power to decide which federal laws are valid and which aren't isn't a power granted to state governments. That is a very important matter, and it's hard to see how the founders could have wanted state goverments to read overriding extra-constitutional state powers into the Constitution. If they'd wanted states to have the right to decide on their own which laws to obey and whether they were or weren't part of the Union, in contradiction of the supremacy clause they'd have made that clear.

The federal government likewise had to turn to the National Guard during Korea, Vietnam, Iraq and probably WWII as well. That doesn't mean that the states are sovereign now. I don't know the exact legal situation of the national guard, but it's not as though the New York National Guard is New York's own army.

Calhoun's theory of government wasn't that of Washington or Marshall. It was quite a questionable theory. Jackson and Madison both rejected it. Most Americans agreed with them in the 1831 nullification crisis. You can find a good overview of constitutional theories here.

The bit about the Civil War changing "the United States are" into "the United States is" is striking, but I'm not sure how solid it is. British usage, and perhaps earlier American usage, requires a use a plural verb for collective nouns. Current US usage doesn't. I don't know all the details, but I wouldn't assume it took a war to change that.

The Civil War did change a lot, but some people assume that everything was the opposite before. If the federal government has power now or if we're one country, they assume the states had to be running things or that we were a loose league of independent states before Lincoln. I'm not sure that's right. The relationship of the federal government and the states and the constitutionality of secession were certainly debateable then. But "debatable" means that people disagreed then, not that the agreed on the opposite of what's accepted now.