The Senate’s habit of filibustering judicial nominees must end. Both Republicans and Democrats are to blame.

Nearly two and a half years after she was first nominated, a candidate for a seat on a federal appeals court in Washington has been denied an up-or-down confirmation vote by Senate Republicans who persist in obstructing President Barack Obama’s judicial appointments.

But the blame must be shared by the Senate’s Democratic leadership, which can’t bring itself to repudiate the undemocratic institution of the filibuster.

Earlier this month, 51 senators voted to end debate on the nomination of Caitlin Halligan to the U.S. Court of Appeals for the District of Columbia Circuit — nine short of the required supermajority necessary to break the filibuster and proceed toward a vote. Only one Republican, Sen. Lisa Murkowski of Alaska, voted in favor of cloture.

Halligan, the general counsel for the district attorney of Manhattan, has been rated “well qualified” by the American Bar Association.

She is being opposed by Republicans on the hoary grounds that she would be a “judicial activist.”

The supposed proof for that assertion is that, as solicitor general for the state of New York, she filed suit against firearms manufacturers seeking to hold them responsible for contributing to the “public nuisance” of gun violence.

Sen. Charles E. Grassley of Iowa, the senior Republican on the Judiciary Committee, complained that Halligan had advanced a “novel legal theory,” which of course is something lawyers often do on behalf of their clients.

Significantly, Grassley also noted that “judges who sit on the D.C. Circuit are frequently considered for the Supreme Court.” In the past, senators of both parties have blocked the appointment to the D.C. Circuit of eminently qualified nominees from the opposing party who were regarded as potential Supreme Court justices.

Democrats derailed two such nominees during the George W. Bush administration, and in 2011 Republicans successfully filibustered Obama’s nomination of UC Berkeley professor Goodwin Liu to a seat on the U.S. 9th Circuit Court of Appeals. (Liu is now a California Supreme Court justice.)

This sort of gamesmanship is outrageous regardless of which party is engaging in it. Senators are free to oppose judicial nominees on any grounds they choose.

The Constitution’s command that the Senate give its “advice and consent” on judicial nominations, however, is thwarted when a minority of senators prevents a floor vote.

We supported Republicans when they threatened to abolish filibusters of judicial nominations in 2005, and we were disappointed that Senate Democrats this year agreed to only minimal changes in the filibuster.

Halligan is paying the price for that timidity, and so are the federal courts.

Editorial by the Los Angeles Times