The U.S. Senate's filibuster flap this week was about confirmation of appointees to the federal executive branch, not the judicial one. The nation's federal judges would be justified in feeling slighted. Their branch of government is as vital to the country as the others, and it has been just as ill-served by Senate gridlock.

That's my take from a report issued earlier this month by New York University's Brennan Center for Justice that decried the uptick in vacancies in U.S. district courts, the first rung in the three-tier federal court system.

Vacancies among the nation's 677 judicial positions in U.S. district courts are running at about 10 percent this year, as they have every year since President Barack Obama took office. That's a significantly higher vacancy rate than in any other recent president's term, and it's causing what the Brennan Center report termed "a crisis" that "limits the capacity of district courts to dispense justice."

The result has been a spike in the average number of pending cases before each judge from around 400 from 1992 to 2008 to about 500 since then. With that increased workload have come delay and greater reliance on "senior status" judges, who come out of retirement to ease the burden on younger judges.

Senate confirmation delays are a key reason cited for the high number of vacancies; 23 nominees were waiting for Senate confirmation as of July 1. But minority senators can gum up the works at the appointment stage too. Senators customarily offer the president the names of candidates for judicial spots in their home states. The report found vacancies particularly prevalent in states represented by two Republican senators, suggesting that they have been slow to submit names to the Democratic president.

Minnesota's U.S. District Court has been spared the vacancy problem – for now. But its seven judges and three active senior status judges are struggling with big case loads, Chief Judge Michael Davis said this week. The local federal court is in line for additional judges – one permanent, one temporary – if Congress agrees to add more judges to the federal district roster.

After enlarging the federal bench every six to eight years since 1960, Congress has not authorized any new federal judgeships since 2003, the Brennan report said. There's more evidence that the legislative branch is neglecting the judicial one.