After Mitch McConnell, the Senate minority leader, emerged from hiding last week to help negotiate an end to the debt crisis, he announced that Republicans would no longer use the same kind of extortion to get their way. “We’re not going to do this again in connection with the debt ceiling or with a government shutdown,” he told The National Review.

If Mr. McConnell is serious about improving his party’s reputation and ending government by threat, there’s an easy first step: Establish a mechanism to prevent the use of the debt ceiling as a weapon. In fact, such a mechanism exists, and the minority leader invented it in 2011. It’s called the McConnell rule, and it’s time to make it permanent before the current agreement runs out on Feb. 7.

This rule, which was used in last week’s settlement and other agreements for the last two years, allows the president to raise the debt ceiling and then gives Congress a chance to disapprove it. If Congress passes a disapproval measure, the president can veto the legislation. The two chambers would then each need a two-thirds majority to override the veto and prevent the debt limit from rising, which is politically unattainable and is likely to remain so.

In any case, the debt ceiling may have reached the end of its useful life last week after President Obama and Senate Democrats refused to negotiate, and Republican leaders showed that they would back down before letting the Treasury default. It’s a World War I-era contrivance that was never used to extract concessions until the Tea Party got hold of it in 2011, and it ought to be formally abolished. It doesn’t limit the debt, which is determined only by the amount Congress spends and takes in. Its only purpose is to give voters the illusion that Congress is acting as a responsible steward over borrowing.