Vik Amar has posted this draft on SSRN. Here is the abstract:

In the weeks leading up to and following Election Day 2020, Republican litigants, taking cues from a minority group of Justices, asked federal courts to undo state election rules on which voters relied in casting ballots. The judges who indicated openness to these requests asserted they have the power and the duty to correct misconstructions of state law by state courts and other adjudicatory agencies. Yet as every good law student knows, misapplication of state law, no matter how extreme, is itself almost always a matter of state law – a problem for state courts to sort out. This teaching comes not just from Erie, but from (among others) a landmark ruling over a century earlier, Green v. Lessee of Neal, in which the John Marshall Court emphatically affirmed the notion that when state courts construe state statutes, those interpretations of state legislative will must be respected by federal courts no matter how fluctuating or wrong-headed state jurists seem to be.

The only exceptions to this – exceedingly rarely relevant and invoked – are instances when state courts misconstrue state law in ways that violate federal norms. And what is the federal norm that has been invoked in this context? That the word “Legislature” as used in Article I, Section 4 and Article II, Section 1 creates a federal entitlement along one or both of the following lines: (1) for the elected state legislature to have its enactments relating to election logistics fully implemented notwithstanding any conflicts between state statutes and state constitutions, and; (2) for the federal courts – assuming state constitutional limits can apply – to decide what those limits (and what the best ways to interpret state statutes) are.

Both halves of this “we-must-protect-the-state-legislatures” theory are not just law-less, in that they are not grounded in the law, but are law-defying, in that they turn federalism on its head. Founding history and structure, as well as binding recent precedent, demonstrate that the theory nonsensically invokes constitutional provisions designed to protect states against federal interference (including from federal courts) and uses them instead to impermissibly disrespect the wishes of the state peoples who create, empower and limit their legislatures, and also the wishes of the elected legislatures themselves.