Dealt a hand he despised by the 2016 election, McConnell, the Republican majority leader, has concentrated on the Senate’s advice-and-consent role in filling the most important appointive offices. Thirty percent of all circuit judges — 53 of them — have been confirmed in the past four years. For the first time in four decades, there are no empty seats on appellate benches (other than Amy Coney Barrett’s). Chief Justice John Marshall extended the influence of President John Adams, who selected him, 34 years beyond Adams’s term. Portions of the judiciary McConnell has shaped will be serving in 2050.

Today, it is painful to watch his final accommodation to the post-2016 reality he has loathed. His chilly comments on President Trump’s resistance to post-election reality (Trump is “within his rights” to “look into” allegations of voting irregularities) reflect only this: Preservation of McConnell’s Senate majority depends on many Trump voters in Georgia’s two senatorial runoffs Jan. 5.

Soon, however, McConnell (Ky.) can turn to restoring constitutional equilibrium between the legislative and executive branches. Moderated Senate behavior would be a radiating balm for the nation and would restore Congress as a counterbalance to the overbearing modern presidency.

No president has had as much congressional experience as Biden. (Gerald Ford and Lyndon B. Johnson each had 24 years, 12 fewer than Biden.) Biden became a 30-year-old senator in 1973. As a 22-year-old, McConnell worked as a Senate intern and later on a senator’s staff before being elected in 1984. With a combined 72 Senate years (so far), Biden and McConnell are custodians of the Senate’s institutional memory.

Already the longest-serving Republican leader, McConnell in 2024 will pass Montana Democrat Mike Mansfield as the longest-serving leader of either party. In 1970, Mansfield made a Senate rule that has enabled behavior that has damaged the institution and embittered national politics. He created the “two-track” system, whereby the Senate can set aside a filibustered bill and proceed to other matters. Hitherto, filibusters had to hold the floor, testing their stamina but inconveniencing the majority, thereby incentivizing accommodation of the minority’s concerns.

The two-track system incites promiscuous filibustering, and erases the implicit principle — rules that lubricate civility often are uncodified — that extraordinary majorities should be required only for extraordinary matters. The Constitution does this by requiring super majorities for proposing constitutional amendments, overriding vetoes and ratifying treaties.

Trivialized filibusters — effectively, a 60-vote requirement for too many things — have fueled the clamor for something neither Biden nor McConnell desires: abolition of the filibuster, which would make the Senate even less deliberative and more acrimonious. But rather than repealing Mansfield’s mistake, it would be wholesome if McConnell and Biden could have recourse, as seasoned professionals do, to implicit understandings.

It could be transformative if they could tacitly agree that post-1970 filibustering has become injurious. If McConnell could get Biden to join him in encouraging all senators to rethink recent norms governing filibustering. And if McConnell could convince Biden to make his administration’s first significant proposal something — say, infrastructure — that has low ideological salience, involves splittable differences, and includes something for everyone. This could nourish a revival of neglected senatorial norms and political mores that have atrophied during recent decades, which could turn down the political thermostat, and wean Washington from its addiction to the gesture-politics of virtue-signaling to inflame the parties’ most fervid members.

McConnell’s skills and tenacity have made him the most important Republican since Ronald Reagan. He is securely in the pantheon of congressional, and national, history, partly because, unlike many senators — most conspicuously, Henry Clay, who McConnell has surpassed as the most illustrious Kentuckian — McConnell has never had presidential aspirations. Perhaps those were precluded because of his (this from National Review) “owlish, tight-lipped public demeanor reminiscent of George Will.” Whatever. His seventh term — only six of 1,984 senators have completed 42 years — will be his apogee if he applies his professionalism to the task of making the institution he reveres function civilly as a counterbalance to the power center 16 blocks away.