A new tradition is developing in the dysfunctional Washington family: the election-year presidential attack on the Senate for blocking judicial nominees.

In his Saturday address, President Obama decried Senate Republican threats to block his nominees, saying “all of the judicial nominees being blocked have bipartisan support.”

The U.S. Supreme Court building (Andrew Harrer/BLOOMBERG)

Obama’s right that Senate Republicans have been particularly aggressive in blocking his nominees, the liberal Alliance for Justice found in a study released last week. The Senate confirmed 81 percent of Clinton’s nominees in the first three years, 78 percent of Bush’s and only 71 percent of Obama’s.

But it’s also true that, while Obama criticizes the Senate for not moving fast enough, Obama’s sent far fewer judicial nominees to the Senate at the end of three years than either Bush or Clinton, even though he’s had roughly the same number of vacancies to fill.

There were also a record number of 30 judicial “emergencies” — defined by the U.S. Judicial Conference as a longstanding vacancy in a busy courthouse.

But it turns out that, at year’s end, there were no nominees before the Senate for 15 of those “emergency” seats — though the Republicans blocked five additional nominees for those seats and slow-walked others.

Administration officials say a chronic problem is that some Democratic senators with judicial vacancies in their states have been extremely slow in proposing candidates — which is how both parties generally select nominees for the lower courts.

Presidents often rightly gripe about this problem, we recall, but it’s quite beside the point. Article II section 2 of the Constitution says the president nominates judges, not senators. “The buck stops here,” Truman said.

It’s expected that most of the 20 nominees now at the Senate Judiciary Committee may be cleared in the next couple of months to join the other 19 on the Senate floor.

Unless Senate Republicans, furious over Obama’s recess appointments, simply shut down all confirmations, there’s a decent chance most of that group of 39 could be confirmed.

But things are going to get dicey after that. We hear that the administration has another couple dozen or so folks ready to be nominated soon, and some more to go into the pipeline after that.

Our hunch is that very few of them will be putting on the robes any time soon because of the dreaded Thurmond Rule — named for the late South Carolina senator, Strom Thurmond.

The “rule,” which apparently dates to 1980, posits that, sometime after spring in a presidential election year, no judges will be confirmed without the consent of the Republican and Democratic leaders and the judiciary chairman and ranking minority member.

On June 12, 2008, Senate Judiciary Committee Chairman Patrick Leahy said that “we are now way past the time” for invoking that rule.

Well, given the GOP mood on the Hill, the Republicans — if they are even allowing judges to be confirmed — may decide that old Strom should be resurrected this year. Maybe, oh, sometime in May.

Most administrations try to put younger judges on the bench. The obvious reasons are that those judges — especially those on the appeals courts — will be able to dominate the courts for longer and will not be too old to fill seats on the Supreme Court.

But the Obama administration’s picks confirmed for appellate courts — the likely place to look for nominees to the Supreme Court — averaged 55.4 years old, the Alliance study found, nearly six years older than Bush’s nominees, nearly seven years older than George H.W. Bush’s nominees and more than four years older than Clinton’s.

Could make for a mighty thin bench available to some future Democratic president.