As President Biden races to fill vacancies on federal courts, voices on the left are pressuring Senate Democrats to end the tradition of “blue slips” — an old custom which allows senators from states where judges serve to veto their selection. It would add more acrimony to the process and further erode faith in the justice system.

 The Constitution requires a president to seek “advice and consent” from the Senate when making lifetime appointments to the bench. Since 1917, the Judiciary Committee has done so by issuing blue pieces of paper to senators from an applicant’s home state since they have the greatest insight into their fitness for the role.

Returning a blue slip, according to the Senate’s website, “does not necessarily mean that the home state senators will vote to confirm the nominee” when the full body votes. “However, it does indicate that the senators elected to represent that state were consulted prior to nomination and that the nominee is likely to be confirmed.”

 President Buchanan is credited with describing the Senate as the world’s “greatest deliberative body,” but like so much of our modern house divided, representatives have grown tired of talking to each other and seek instead to crush opposition.

Thanks to winning a 51st seat in November, Democrats have a majority on the Judiciary Committee, so they no longer need Republican votes to advance nominations, but the blue slip remains a means by which the minority party can block judges from ascending.

Both parties have eroded the privilege. When Mr. Biden was the Judiciary committee chairman some 40 years ago, he let nominations proceed if senators refused to return their blue slips, although he stipulated that the White House had to consult home-state senators before putting forward a name.

In 2017, the Republican chairman of the Judiciary Committee, Senator Grassley, said that while he was “less likely to proceed on a district court nominee who does not have two positive blue slips,” he’d do so on circuit courts since they “cover multiple states,” saying Democrats couldn’t “expect to use the blue slip courtesy” in place of the filibuster they’d abolished.

Now activists are pressuring Democrats to whipsaw courts back in their favor. In an editorial on Monday, the New York Times wrote “home-state veto power is a fundamentally undemocratic practice that gives far too much power to individual senators.”

In September 2017, the Times was less enthusiastic of Republicans abolishing slips, quoting the Democrats’ minority leader, Senator Schumer. “Getting rid of the blue slip would be a mistake,” he said, and a retired Democrat from Minnesota, Senator Franken, wrote in 2021 that “ending the blue slip damaged the courts forever.”

Now, the fickle shoe of power is on the other foot and it’s time to kick the GOP back. “Republicans have made a mockery of the blue slip system,” the Democrat from Connecticut, Senator Blumenthal, told CNN. “I’m counting on our leadership, the chairman to impose some discipline and order on this process.”

The chairman from Illinois, Senator Durbin, now says blue slips are “a good thing, but we need cooperation.” Readers fluent in the Beltway dialect know to disregard whatever a politician says before “but” and that “cooperation” means capitulation on the speaker’s terms.

This tit for tat bodes ill for equal justice under the law. Citizens have an expectation that the judge is putting the law first and has the broadest support possible regardless of who appointed them, an ideal championed by Chief Justice Roberts in 2019.

“We do not have Obama judges or Trump judges, Bush judges or Clinton judges,” Chief Justice Roberts said. “What we have is an extraordinary group of dedicated judges doing their level best to do equal right to those appearing before them,” an ideal of impartiality.

So far, Mr. Durbin is maintaining the blue slips that force senators to seek consensus. It may be too much to expect him or a future GOP chairman to stick to that high road, but if the partisanship rolls on, Americans will keep losing faith in the courts and the Senate will skid into being nothing more than the world’s pettiest deliberative body.