One of the few areas of progress in recent months has been the confirmation of judges by the Senate. Under a deal in the spring, 17 judges got confirmed, stretched out over a period of several weeks. And when that deal expired, a few more judges trickled in with confirmations. In all, 20 judges have been confirmed in the last two months, according to Sen. Chuck Schumer; and just on Tuesday, the Senate confirmed Andrew Hurwitz to the 9th Circuit Court of Appeals, getting cloture on the nomination with a super-majority of exactly 60 votes. There are still an undue number of vacancies on the federal bench – and part of that can be chalked up to the Administration not nominating enough judges – but the situation was improving somewhat.

Until now.

With less than four and a half months until Election Day, Senate Republicans are shutting off the bipartisan spigot when it comes to confirming President Barack Obama’s nominees to the nation’s top courts and will present a unified front against his circuit court picks through November.

Senate Minority Leader Mitch McConnell (Ky.) made the decision to blockade nominations official Wednesday when he informed his colleagues that he would invoke the “Thurmond Rule” from now until after the elections.

Named after the late Sen. Strom Thurmond (R-S.C.) — and alternately called the “Leahy Rule” by some Republicans after Judiciary Chairman Patrick Leahy (D-Vt.) — the doctrine holds that within six months of a presidential election, the opposition party can, and typically does, refuse to allow votes on circuit court judges.

Republicans claim that Patrick Leahy engaged in this practice at the end of the Bush Administration. Circuit court judges, therefore, would be obstructed for the rest of the year, while district court judges could still get confirmed between now and September.

But the “Thurmond rule” goes back to 1968, and Thurmond’s blocking of Abe Fortas for the Chief Justice of the Supreme Court that year. And it has not uniformly held. As Ian Milhiser reports, past Presidents have had circuit court judges approved between June and September of an election year, including George W. Bush, who Republicans claim Leahy prevented from those confirmations:

President Carter had 5 appeals judges confirmed between this day in 1980 and that year’s election, one of whom was future Justice Ruth Bader Ginsburg. President Reagan had 7 in his first term and 2 in his second. The first President Bush had 7. No appellate judges were confirmed in the lead up to the 1996 election, but one was confirmed at the end of President Clinton’s second term. The second President Bush had 3 confirmed during this period in 2004 and 2 in 2008.

In 2004, Orrin Hatch denied the existence of the Thurmond rule and continued to press for judicial confirmations until the Senate went out of session. The only real honoring of the Thurmond rule in the past 40 years came when, you guessed it, under a Democratic President and a Republican Senate, in 1996 and 2000 with President Clinton.

Leahy basically invoked all of this in remarks today, saying he would keep pressing for confirmations. There are currently 75 judicial vacancies, and Congress doesn’t have much else they can agree on, freeing up plenty of time on the Senate floor. Leahy will probably start with judges in states with Republican Senators, like Maine and Oklahoma, where the GOP members have a vested interest in the outcome.

But if Republicans stand strong in opposition – and that’s probably the thing they do the best – we’ve seen the last confirmed circuit court judge for 2012.