This is simply an outrageous abuse that further undermines the integrity of the Senate.

Senate Republicans on Tuesday filibustered the nomination of Caitlin Halligan to the U.S. Court of Appeals for the District of Columbia Circuit, blocking a nominee tapped last year by President Obama to serve on one of the country’s most powerful courts.

Tuesday’s final roll call vote on cutting off debate was 54 to 45.. One Republican — Sen. Lisa Murkowski (R-Alaska) — joined all 53 members of the Democratic caucus in voting to move ahead with Halligan’s nomination, leaving the former New York state solicitor general six votes short of the 60 votes necessary for ending debate.

Sen. Orrin Hatch (R-Utah), who has never voted to filibuster a judicial nomination, voted “present.”

The “Gang of 14” struck a deal six years ago, limiting judicial filibusters to “extraordinary circumstances.” That deal now appears to be dead — all of the Gang’s Republican members who are still in office joined the filibuster of Hilligan today. That includes so-called moderates like Susan Collins, Olympia Snowe, and Scott Brown.

Maybe, the GOP might argue, Hilligan counts as being so “extraordinary” her nomination cannot be subjected to a vote? Hardly. She’s a clearly qualified former New York solicitor general who has earned wide, bipartisan praise. A joint letter from 21 attorneys who’ve worked with her, including some high-profile conservatives like Miguel Estrada, explained, “Caitlin also has an ideal judicial temperament. She brings reason, insight and judgment to all matters. Even those of us who have been on opposite sides of Caitlin in litigation have been greatly impressed with her ability and character. We have no doubt that she would serve with distinction and fairness.” A joint letter from several law-school deans and professors added, “Ms. Halligan’s legal credentials, experience, and accomplishments make her exceptionally well-qualified to serve on this court.”

And yet, 46 out of 47 Republican senators wouldn’t even give her a vote. Why? Because they said Halligan is sympathetic towards marriage equality and once signed a brief in a liability suit against gun manufacturers. Even for the alleged moderates, that was enough.

They could have voted against her, but these GOP senators said that wasn’t good enough.

What’s more, let’s not forget what many of these same Republicans said about judicial filibusters before there was a Democratic president. For some, their own actions today weren’t just wrong; they were literally unconstitutional.

Here’s a list ThinkProgress put together in May:

Lamar Alexander (R-TN) : “I would never filibuster any President’s judicial nominee, period. I might vote against them, but I will always see they came to a vote.”

Saxby Chambliss (R-GA) and Johnny Isakson (R-GA): “Every judge nominated by this president or any president deserves an up-or-down vote. It’s the responsibility of the Senate. The Constitution requires it.”

Tom Coburn (R-OK): “If you look at the Constitution, it says the president is to nominate these people, and the Senate is to advise and consent. That means you got to have a vote if they come out of committee. And that happened for 200 years.”

John Cornyn (R-TX): “We have a Democratic leader defeated, in part, as I said, because I believe he was identified with this obstructionist practice, this unconstitutional use of the filibuster to deny the president his judicial nominations.

Mike Crapo (R-ID): “Until this Congress, not one of the President’s nominees has been successfully filibustered in the Senate of the United States because of the understanding of the fact that the Constitution gives the President the right to a vote.”

Chuck Grassley (R-IA): “It would be a real constitutional crisis if we up the confirmation of judges from 51 to 60, and that’s essentially what we’d be doing if the Democrats were going to filibuster.”

Mitch McConnell (R-KY): “The Constitution of the United States is at stake. Article II, Section 2 clearly provides that the President, and the President alone, nominates judges. The Senate is empowered to give advice and consent. But my Democratic colleagues want to change the rules. They want to reinterpret the Constitution to require a supermajority for confirmation.”

There are other examples. Sen. Jim DeMint (R-S.C.) said “denials of simple votes on judicial nominees” are “unconstitutional.” Sen. Lindsey Graham (R-S.C.) said, “I think filibustering judges will destroy the judiciary over time. I think it’s unconstitutional.” Sen. Richard Shelby (R-Ala.) argued, “Why not allow the President to do his job of selecting judicial nominees and let us do our job in confirming or denying them? Principles of fairness call for it and the Constitution requires it.”

How many of these senators filibustered Halligan’s nomination today? All of them.

What’s more, senators like Scott Brown, Susan Collins, Olympia Snowe, and John Thune had never supported a judicial filibuster in their careers before 2011. How many of them refused to allow a qualified nominee to have an up-or-down vote? All of them, too.

What an embarrassment.

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.