In case you need more evidence of how much damage keeping the filibuster might end up doing, add this to the list: It could make a future stolen presidential election more likely.

This is thrust upon us by new revelations about the extent of Donald Trump’s efforts to overturn his 2020 loss — and by an important new paper by a leading legal scholar warning of future election subversion. Both should prompt new urgency among Democrats.

The revelations come from the new book “Peril,” by The Post’s Bob Woodward and Robert Costa. The headline: Two GOP senators — Lindsey Graham of South Carolina and Mike Lee of Utah — took Trump’s lies about election fraud seriously enough to devote real resources to vetting them.

But for our purposes, the more important revelation involves how those lies were supposed to interlock with the broader scheme cooked up by Trump and his co-conspirators.

The key takeaway: Gaping holes in the Electoral Count Act — the 1887 law that governs how Congress counts electoral college votes — were central to the chances that their scheme might succeed.

The book recounts that four days before Jan. 6 — when Congress counts the electoral votes — Lee received a White House memo outlining how Vice President Pence could scuttle the process, according to a new Post piece about the book.

Because Republicans in several swing states had voted to send sham electors for Trump to Congress, it argued, Pence could simply set aside the actual electors from those states for President Biden. Both sets would be invalid, and Pence could count the remaining electors, designating Trump winner of a majority of them.

The memo suggested this as a potential option, and it also suggested Pence could use objections by GOP lawmakers to Biden’s electors to delay the process. The book reports that Pence explored this idea before rejecting it.

Let’s be clear: The fact that these ideas were considered this seriously was made possible in part by the absurd ambiguities in the Electoral Count Act, or ECA.

Dangerous ambiguities

First, because the ECA provides that a state can appoint new electors if the election “failed” — which is defined very vaguely — the idea was to use “election fraud” lies to declare that popular voting “failed” to render a clear outcome. GOP legislatures could then appoint electors for Trump, regardless of their state’s popular votes.

Second, because the ECA makes it easy for Congress to object to electors — only one lawmaker from each chamber can force votes on whether to count them — the idea was to get congressional Republicans to invalidate Biden’s electors in key states. Trump would prevail with a majority of remaining electors.

Third, because the ECA does not clearly define the vice president’s role (as president of the Senate) as purely ceremonial, the idea was to get Pence to somehow rule in favor of the objections to electors, or at least to delay the count.

That would either result in Trump prevailing with a majority of electors, or buy enough time for GOP legislatures to send rogue electors. Remember, getting Pence to rig or delay the count was precisely what Trump incited the Jan. 6 mob to accomplish.

A ‘respectable bloodless coup’

In a great new draft paper, election law scholar Richard L. Hasen warns that we face “serious risk” of “election subversion” or an “actual stolen election.” Hasen discusses reforms that could avert such scenarios, which will also be the topic of a conference on Friday.

In the last election, no GOP legislature appointed rogue electors, a majority of Congress voted to uphold Biden’s electors, and Pence ultimately backed away from the plot. But some GOP legislators did consider this scheme, around 150 congressional Republicans did vote to subvert Biden’s electors, and Pence did explore the outer limits of what he might do for Trump.

And if the GOP controls the House and Senate on Jan. 6, 2025, Congress can simply count rogue electors sent by a given state, or refuse to count the rightful ones. If Republicans control just the House, Congress might deadlock, prompting a contingent election in the House decided by state delegations, and the Republican would win.

Indeed, as Hasen notes, the scheme getting even this far shows we are vulnerable to a future “respectable bloodless coup,” one “dependent upon technical legal arguments overcoming valid election results." This, plus the fact that some Republican candidates are now campaigning on a vow to subvert future losses, requires cutting off these pathways.

So Hasen recommends dramatically raising the threshold for Congress to object to electors; rewriting rules to make “frivolous objections” harder; and defining “failed” elections as only resulting from natural disasters or terrorist attacks, to forestall states sending rogue electors. Hasen also recommends mandating that states follow procedures making it harder to corrupt the appointment of electors.

Other ECA reforms suggested by election experts include clarifying that Congress must count a state’s legitimately determined electors, and that the vice president has zero role in deciding disputes over the electoral count.

Democrats should push for ECA reform, and I expect they will. But nothing will pass as long as the filibuster remains.

“The window is closing,” Hasen told me. “The filibuster is the major impediment to Congress taking steps to avert a potential stolen election in 2024.”

Do Democrats grasp the true urgency of this? It’s not clear that they do.