Each state is POPULARLY sovereign: i.e. the each citizen of the state, is a SUPREME RULER of that state; and together, they constitute the RULING SOVEREIGNS of that state. That's called DEMOCRACY– i.e. each person, being naturally endowed with inalienable rights, simply DELEGATES authority to a subordinate representative in government; the government or state does not OWN that power…. or that PERSON.

So only THE PEOPLE of a state, can overrule the federal government– and they can do so by popular vote in a state convention called for that purpose.

Naturally, this was suppressed by mass-murder and censorship beginning in 1861, and it never stopped: i.e. popular state sovereignty is the LAW, but it has been quashed by the federal Amerikan empire for the past 150+ years.

"The key, of course, is the italicized phrase. All laws made in pursuance of the Constitution, or those clearly enumerated in the document, were supreme…"

"Clearly" in whose judgment?
In order to poperly "nullify" a federal law, requires the majority of a state's PEOPLE to vote such a decree in a state convention; without this popular mandate, the state government can't simply thump the Constitution and do so on their own authority, citing the "Tenth Amendment. "
This movement is barking up the wrong tree, as always.