Forgive Americans if they no longer remember that the elephant is the symbol of the Republican Party. Elephants are supposed to never forget, yet Republicans seem more than happy to memory-hole the Jan. 6 U.S. Capitol riot, as GOP members of Congress find absurd reasons to oppose a bipartisan commission to examine the beginnings and unfolding of an attempt to upend a presidential election.

It’s yet another aspect of the party’s service to a former president insistent on warping the facts of a general election he refuses to admit that he lost. And it’s yet another piece of evidence that the party itself shares his delusion.

Call this affliction the New McCarthyism, after House Republican Leader Kevin McCarthy. He first forced out Liz Cheney, the No. 3 Republican, who pointedly refused to go along with Donald Trump’s nonsense. He then performed a flip-flop for the ages.

McCarthy assigned Rep. John Katko of New York to negotiate the nature of the commission – a 10-person panel, equally divided between out-of-office politicians of both parties. Katko gave McCarthy precisely what he wanted, which turned out not to be enough.

Separately, McCarthy stood by as members such as Andrew Clyde of Georgia claimed that it was a lie to call the Jan. 6 riot an “insurrection” because, in fact, it was not too dissimilar from “a normal tourist visit” of the Capitol. Shortly afterward a journalist tweeted a photo of Clyde helping to barricade the doors to the House floor, attempting to keep out the invading hordes.

It’s all but certain that McCarthy is doing this because he fears personal exposure. In the days after the attack, McCarthy told other Republicans that he had a tense call with the White House on Jan. 6 in which he urged Trump to call off the assault on the Capitol. One week later, he said on the House floor: “The president bears responsibility for Wednesday’s attack on Congress by mob rioters.”

Since then, McCarthy has been all in on getting back into Trump’s good graces.

McCarthy’s flip-flop may have inspired his Senate counterpart, Minority Leader Mitch McConnell, to do his own. This is the same man who gave one of the most devastating rhetorical takedowns of Trump at the impeachment trial (even as he voted to acquit). “There’s no question that President Trump is practically and morally responsible for provoking the events of the day,” he declared on Feb. 13.

McConnell now deems the House bill – which, remarkably, still got 35 Republican votes – “slanted and unbalanced,” even though it was a negotiated compromise.

Approving such a process would apparently get in the way of the GOP’s “midterm message.” And so senators such as Mike Rounds of South Dakota supported the commission on one day but opposed it the next. Even senators who voted to convict Trump in his February impeachment trial, such as Richard Burr of North Carolina, deemed the commission unnecessary.

It is anything but. Yes, there are other inquiries into the events of that day. But there are many questions that won’t be answered by prosecutions of the insurrectionists:

Precisely what did Trump tell McCarthy when the Republican leader pleaded for the president to get his supporters to stand down? Why wasn’t the National Guard promptly activated? How aware was the president that his vice president was in imminent harm’s way? Why did it take hours for the president to record a video to his supporters storming the Capitol? Why did he still validate their violent behavior with another affirmation that the election was “fraudulent” and that he “loved” them? Did any members of Congress encourage the rioters?

Senate Majority Leader Chuck Schumer vows a vote on the commission as early as this week. If Republicans block that vote, perhaps the Democrats should adopt the stubbornness of the donkey that has long been their symbol – and force Republicans to defend on the Senate floor why they would prefer not to explore the events of Jan. 6. If Republicans want to block an official inquiry into an unprecedented insurrection, let them pay a public political price.

After which, if Senate Republicans succeed in wielding the filibuster to kill the commission, then Democrats will have no choice: Form a select congressional committee and pursue the truth. To ignore the roots of the insurrection would be to further encourage the ongoing anti-democratic behavior of Trump partisans across the country – and guarantee that future assaults are all but inevitable.

Robert A. George writes editorials on education and other policy issues for Bloomberg Opinion. He was previously a member of the editorial boards of the New York Daily News and New York Post.