Running for president in 1968, Alabama Gov. George Wallace thought he spotted a problem: “We got too much dignity in government.” Thirteen presidential elections later, voters solved that problem. Now they can make amends by closing the Donald Trump parenthesis in U.S. history.

The first, and almost certainly the last, public service for which he is actually responsible is his decision to run again. This gives the nation an occasion for self-correction. When the Republican nomination is denied to him he will, of course, pronounce the process rigged. By then, few will care.

Among the Republican nominating electorate, Trump has a floor of forever Trumpers, but the floor is sagging.

His 2016 victory was sealed by wafer-thin margins (a combined 77,744 votes out of 13,940,912 cast) in Michigan, Pennsylvania and Wisconsin. All three just elected Democratic governors, two (Gretchen Whitmer in Michigan and Josh Shapiro in Pennsylvania) by landslides over notably supine Trump grovelers who were out of their depths and minds.

When Mahatma Gandhi was asked what he thought about Western civilization, he supposedly said he thought that would be a good idea. The same can be said of the “Republican establishment.” It should act as an establishment, working to impede a proliferation of presidential candidates who would allow the Trump rump of the party to prevail.

When at the 2016 Republican convention Trump boasted that “I alone can fix it,” the approving roar obscured the roarers’ vagueness concerning the antecedent of his pronoun: What would he fix? The achievement of Trump’s tenure, the transformation of the federal judiciary, was accomplished by someone whose loathing of Trump exceeds Trump’s loathing of him: Mitch McConnell, establishmentarian.

What handhold can Trump, the entertainer turned bore, now grasp to stop his current slide? He has always been a Potemkin tycoon, parasitic off the superstition that great wealth is somehow symptomatic of other greatness.

Florida Gov. Ron DeSantis, who is as serious about governance as Trump was frivolous, last week assembled an electoral coalition in the nation’s third-most populous state that was broader than Trump ever assembled anywhere. DeSantis is the first, but not the only, plausible claimant to the leadership of the Republican Party.

Wallace, who was a Trump precursor, had a precursor. Huey Long, architect of a Louisiana police state, was America’s first dangerous demagogue of the era of mass communication, which dawned before television and social media: On radio. Long was Willie Stark in Robert Penn Warren’s 1946 roman ‘clef, “All the King’s Men.” In it, Warren’s protagonist is advised: “Make ’em cry, or make ’em laugh … Or make ’em mad. Even mad at you. Just stir ’em up … and they’ll love you and come back for more.”

Until, weary of repetitions, they don’t.

An assassin prevented Americans from proving, by spurning Long’s presidential pretenses, that they were less easily gulled than Long assumed. The republic deserves, and the GOP needs, what Trump Tuesday evening announced: An opportunity for them to prove, by giving him a bruising rendezvous with their repentance, that they are better than he thinks.