WASHINGTON (AP) — Carrying out their threat to block appeals court nominees as the fall elections approach, Senate Republicans on Monday blocked confirmation of a U.S. appeals court nominee from Oklahoma despite his bipartisan support.

Robert Bacharach's nomination to the 10th U.S. Circuit Court of Appeals was filibustered because of an unwritten rule that says a party may block a judicial nominee when it believes the White House will change hands. Republicans hope that Mitt Romney will be elected and make his own nominations for the federal courts.

Bacharach's home state Republican senators, Tom Coburn and James Inhofe, said the nominee was well qualified but they went along with the approach. They voted present.

The Senate vote was 56-34 on a motion to allow the confirmation to proceed, short of the 60 needed to end a filibuster.

Inhofe said it was "awkward" not to vote for "one of the best nominees."

Inhofe added, "The problem ... is that this will be the latest confirmation of a circuit court nominee during an election year in 20 years. I was thinking just today that I cannot vote against this guy, but I sure can just vote present." He said he didn't want to break a 20-year precedent.

Coburn called Bacharach, a magistrate judge, "a stellar individual, rated very highly qualified by the American Bar Association." He called the unwritten rule "stupid," but said he wanted to support the prerogatives of the Senate.

Democrats call the tactic the "Thurmond Rule," named for late Republican Sen. Strom Thurmond of South Carolina — a onetime chairman of the Judiciary Committee. Republicans call it the "Leahy-Thurmond Rule," adding the name of Sen. Patrick Leahy, D-Vt., the current committee chairman.

Leahy said the Republican filibuster is "another example of how extreme Senate Republicans have gone in their efforts to obstruct judicial confirmations. Never before has the Senate filibustered and refused to vote on a judicial nominee with such strong bipartisan support who was voted out of the Judiciary Committee with virtually unanimous support."

In a written statement, White House Counsel Kathy Ruemmler said, "The American people deserve better than this unprecedented partisan obstruction of the president's efforts to ensure a fair and functioning judiciary."

Nearly 1 in 11 federal judgeships are empty currently, she said. Ruemmler added, "The judicial vacancy rate has never been this high for this long."

There are 20 judicial nominees waiting for consideration by the Senate. Half of them would fill vacancies deemed judicial emergencies.

The 10th Circuit hears appeals in Oklahoma, Kansas, New Mexico, Colorado, Wyoming and Utah, plus those portions of the Yellowstone National Park extending into Montana and Idaho.