Rick Hasen notes a ticking time bomb at the tail end of Moore v Harper. Here it is, edited to shorten:

In the last part of his majority opinion for the court, the chief justice got the liberal justices to sign on to a version of judicial review that is going to give the federal courts, and especially the Supreme Court itself, the last word in election disputes. The court held that “state courts may not transgress the ordinary bounds of judicial review such that they arrogate to themselves the power vested in state legislatures to regulate federal elections.”

To understand these dense words, we need to go back to the last time the Supreme Court decided a major election case, the 2000 Bush v. Gore decision (a case cited in Moore, for the first time ever, in a majority opinion in the 23 years since that decision).  ....

After the Florida court ordered the recount, Bush appealed to the U.S. Supreme Court. A majority held that the recount ordered by the Florida court violated the equal protection clause because there was no guarantee that uniform standards were used or could be used to conduct it. But three justices—Chief Justice William Rehnquist, joined by Justices Antonin Scalia and Thomas—adopted this milder version of the independent state legislature theory at the time. In essence they argued that the Florida court’s interpretation of the Florida election statutes to allow this recount was so far from ordinary statutory interpretation that the Florida court was essentially making up the law for itself, and taking away the legislature’s power to decide the rules for conducting federal elections in the first instance. 

It is this milder version of the independent state legislature theory that the court embraced in Moore. It did not spell out its contours, and whether to adopt the Rehnquist Bush approach or some other approach. But Kavanaugh, in a concurrence, endorsed the Rehnquist approach and said that in engaging in this second-guessing, federal courts need to compare election law in the state in earlier decisions. The greater the deviation, the more likely they’d be to find a violation of the independent state legislature theory. 

Make no mistake: This apparent new test would give great power to federal courts, especially to the U.S. Supreme Court, to second-guess state court rulings in the most sensitive of cases. It is going to potentially allow for a second bite at the apple in cases involving the outcome of presidential elections. In the 2020 presidential election, for example, Trump allies raised this theory in arguing that Pennsylvania’s Supreme Court could not extend the days for the receipt of absentee ballots by three days in light of the COVID-19 pandemic. There were not enough of these late-arriving ballots to make a difference in 2020, but if there had been, according to the approach laid out in Kavanaugh’s concurrence, the Supreme Court would have had to look at Pennsylvania court precedents to decide if the state court went too far in deciding matters under its own state laws. ...

It fell to Thomas, who ironically joined Rehnquist’s Bush concurrence, to point out how much discretion Roberts’ test. ...

Thoughts?

First, besides the time bomb, is the making Bush v Gore precedent now, explicitly rejecting Rehnquist, speaking for the five kingmakers, saying that it shouldn't be, and even that it wasn't.

Second, Roberts has dropped such time bombs ever since being the fifth vote on upholding Obamacare — at the price of truncating the Commerce Clause by calling the penalty a tax, and other things. And, he's used that in years since.

Although the Court upheld Section 2 of the Voting Rights Act earlier this year, that would be one way this could come into play in the future — keeping it technically still alive, but further narrowing its parameters.

Or, in the case of absentee ballots, things such as what counts as a defaced ballot, equal access and drop-off locations and more will all be in play for federal review.