For President Biden to succeed, the Democrats must find a way to limit the Republicans’ use of the filibuster, the procedural weapon in the Senate that requires 60 votes to advance legislation to a vote and threatens to leave the new president’s agenda in purgatory.

On Monday, the newly demoted Senate minority leader, Mitch McConnell of Kentucky, relented on his demand that Senate Democrats preserve the filibuster, and he agreed to move ahead with discussions on a power-sharing agreement. But the filibuster still lives: At least two Democrats have said they oppose ending it, enough to frustrate any effort by Democrats to do so by a majority vote in the 50-50 Senate.

So long as Mr. McConnell holds those two cards, any Democratic threat to end the filibuster altogether — the so-called nuclear option — is doomed. This leaves Mr. McConnell with a potential veto over most of the Biden legislative agenda.

But what if a genuine compromise were possible that preserved the Senate filibuster as a protection of individual conscience while giving President Biden a fair shot at enacting a desperately needed Covid-19 relief package? Such a compromise exists, we believe, by restoring the original “speaking filibuster,” made famous by Jimmy Stewart in “Mr. Smith Goes to Washington,” in place of the modern version.

In the beginning, from 1789 to 1806, debate in the Senate could be ended at any time by majority vote. In 1806, the Senate abolished that rule, leaving no way to cut off debate. This decision gave birth to the filibuster to delay or block legislative action. This involved a senator holding the floor continuously, as Mr. Smith did (not easy), or to act in carefully choreographed relays with like-minded colleagues (also not easy) and prevent a vote on the merits.

Still, a few successful filibusters were maintained, most notoriously to block anti-lynching and other civil rights legislation, but only when opposition was so passionate that senators were willing to endure the physical and logistical rigors of seizing the Senate floor and refusing to let go. In 1917, opponents of the United States’ entry into World War I were able to sustain such a speaking filibuster, blocking widely supported legislation that would have enabled merchant vessels to arm themselves. An angry Senate reacted by adopting formal rules that allowed an end to debate by a vote by two-thirds of the senators present on the floor.