You put in bold the very reason the given state does NOT have to follow that clause if it chooses not to. The state governor issues an executive order declaring a certain individual invalid and ineligible.
Done. Stroke of the pen, law of the land- kinda cool, huh?
You’re right. A governor could do that. It would promptly be overturned by a court on the accurate basis that a state governor is given no power by the Constitution to interfere in presidential elections.
You seem to suffer from a common delusion about an executive order. An EO is valid if it directs implementation of a power already held by a president or governor. If it goes beyond these bounds, it has no legal validity.
You claimed that a sovereign state is not bound to abide by federal law if it disagrees. I quoted the Constitution itself to the contrary. You wish to address this discrepancy?