Excellent questions. With regard to “the Supreme Court” and the “authority to overrule...state laws when they conflict with the Constitution,” such action would require the court (if I remember Mr. Justice Marshall’s words correctly) to ‘say what the Constitution means.’ Is that a proper function for the federal government? Thomas Jefferson thought not:
“...(T)he government created by this compact was not made the exclusive or final judge of the extent of the powers delegated to itself; since that would have made its discretion, and not the Constitution, the measure of its powers...”
James Madison thought not (as noted above); and the delegates to the Philadelphia convention thought not, having debated the issue repeatedly, and rejected it repeatedly. John Taylor made a rather pointed observation: “(i)n all treaties, the right of construction [i.e., interpretation] must be attached to the right of alteration, or the latter right would be destroyed.” If so (and his analysis is difficult to fault), then one may choose to argue that “three fourths of the several States” must agree as to any interpretation of the Constitution. But one may not consistently argue that any part of the federal government may ‘say what the Constitution means,’ because the Constitution delegates no power whatsoever to the federal government to “alter” the compact. And yet, in the end, that is precisely what we allow the high court to do today.
Otherwise you have 50 different bodies interpreting the Constitution. Fifty different interpretations of the Second Amendment. Fifty different interpretations of the 16th Amendment.
When the federal government passed into law the “palpably unconstitutional” Sedition Act, we did not see a dozen or more “different interpretations” of the Constitution: we saw two. The Northern States (the ‘base’ of the Federalist Party) tended to support the right of the federal government to arrest those who criticized the Federalist President; a minority of States (mostly Southern) opposed the unconstitutional federal action. In the meantime, at least three Supreme Court Justices were prosecuting, fining, and imprisoning Americans for criticizing the President.
In your scenario, the Northern states in 1858 were well within their rights to refuse to enforce the fugitive slave act if their interpretation of the Constitution said that they needn't. I'm not sure I see the advantage of that.
Absolutely true – and the Southern States were equally “well within their rights” when they elected to withdraw from the union. But please bear in mind: the Republic had existed for eight decades prior to the Southern secessions without the departure of a single State. And if the right of the States to judge “in the last resort” had been acknowledged by federal officials as well as the States, the matter would likely have been resolved peacefully.
I must agree with Mr. Jefferson: I see no "advantage" to allowing the federal government to be "the exclusive or final judge of the extent of the powers delegated to itself." Given the historical record of human government, that is akin to allowing the fox to guard the hen house...
;>)
Bingo. BTTT.