As the Jan. 6 select committee kicks into high gear, one big thing it will examine is the role played by Mike Pence in the final days of Donald Trump’s effort to overturn his presidential reelection loss and remain in power illegitimately.

As vice president, Pence ultimately rebuffed Trump’s pressure on him to halt the congressional count of electors and declare Trump winner. Whether he did so after seriously entertaining this scheme, and what other bad actors pressured him to execute it, are things we need to learn about.

But we also need to do something else: We must kill off the dangerous legal theory that Trump and his co-conspirators hatched to justify that scheme, so it never rises again.

Some new reporting on Pence’s role, combined with a new analysis of that legal theory, should give us the hook for this. It’s important, because there are new signs this legal theory remains alive, though in staggering zombie form.

The theory is the one in the now-notorious Trump coup memo. Lawyer John Eastman outlined a scheme for Pence to ignore federal law and refuse to count President-elect Joe Biden’s electors, making Trump winner. Eastman discussed the theory with Trump and Pence a couple days before Jan. 6. Pence was unpersuaded.

A new book by reporter David M. Drucker adds more detail to Pence’s handling of Trump’s pressure. As Drucker reports, Pence’s top advisers — counsel Greg Jacob and chief of staff Marc Short — deeply researched the theory and decided Pence should disavow it, which he did on Jan. 6.

We already know some of this from Bob Woodward and Robert Costa of The Post. Their account is more damning: Pence apparently went to great lengths to try to make the theory operative.

But Drucker has added something useful: According to his book, Pence’s advisers unequivocally and definitively concluded the theory is wholly illegitimate from top to bottom.

The Trump coup theory

The theory in the Trump coup memo is that the vice president has unilateral power — in his role as president of the Senate — to decline to count electors sent to Congress by states.

This theory is based in part on this from the 12th Amendment: “The President of the Senate shall, in the presence of the Senate and House of Representatives, open all the certificates and the votes shall then be counted.”

The theory extrapolates from this the notion that the vice president alone, and not Congress, does the counting. As Eastman’s memo claims, “all the members of Congress can do is watch.”

The theory also extrapolates from this the idea that the Electoral Count Act, or ECA — the 1887 law setting the process for counting and resolving disputes over electors — is unconstitutional. Why? Because it gives Congress that role, and the 12th amendment supposedly gives it only to the vice president.

In the coup memo theory, this should have allowed Pence to disregard the ECA as unconstitutional. Pence could unilaterally delay the count of electors, then a few swing states won by Biden could have decided the voting was illegitimate and sent new electors for Trump, then Pence could unilaterally decide the dispute by refusing to count either set of electors. Trump wins.

In the new book by Drucker, Pence’s advisers flatly declare this illegitimate. Pence’s chief of staff says, “no limited-government conservative would ever advocate that one person could unilaterally choose what electors to accept or reject and would ever be given that sort of power by our founders.”

Yet this zombie legal theory still lives on in the Trumpian intellectual universe.

Kill the zombie for good

Recently, Claremont Institute — the think tank that employs Eastman and is developing a demented intellectual theory of Trumpism — put out a statement denying that Eastman ever suggested Pence should throw the election.

That’s nonsense — Eastman’s memo said exactly that — but regardless, Claremont whitewashed the situation in a way that leaves the zombie theory alive. Claremont claimed Eastman advised Pence not to assume unilateral authority “despite credible legal arguments” saying he does have that authority. The theory lives on.

It shouldn’t. Which brings us to a comprehensive new analysis by legal scholar Matthew Seligman.

Seligman’s essay notes that the 12th Amendment doesn’t assign the counting role only to the vice president. A more reasonable reading is that the vice president “opens” slates of electors and they “shall then be counted” by all present, including Congress.

Seligman also does a deep historical dive into the two presidential elections before the 12th Amendment’s 1804 ratification. In both, Congress did count electors (via a complex procedure) and much contemporaneous discussion demonstrates a clear understanding of this.

It’s impossible to believe the 12th amendment would have assigned this counting power only to the vice president right after all that, Seligman notes.

“Congress has participated, and in important respects controlled, the count of electoral votes from the very beginning,” Seligman concludes. This shows the 12th Amendment was ratified to reflect precisely that understanding, that “Congress, and not the President of the Senate,” counts and resolves disputes over electors.

Election law scholar Lawrence Lessig calls this the “definitive takedown” of the coup memo theory.

But it’s not a small thing that neither Claremont nor Eastman have disavowed it, particularly with Republicans possibly gearing up for some sort of rerun.

So we need to hear from Pence’s advisers publicly on this at greater length, and from other conservative legal scholars. And hopefully there will be an occasion to grill Eastman on it.

Guess who could do this very effectively? The Jan. 6 select committee could.