Washington (CNN) -- Senate Republicans voted Tuesday to filibuster President Barack Obama's nominee to fill a seat on the U.S. Court of Appeals for the D.C. Circuit, because they complained she is too liberal and would be an activist on the bench.
The largely party-line vote was 54 to 45, falling shy of the required 60-vote threshold to end the cloture stalemate and allow a final vote on the nomination itself.
Obama said in a statement he was "deeply disappointed."
Caitlin Halligan, a top lawyer in the New York County District Attorney's Office, was nominated last year to what is often regarded as the second most influential court in the land, both because it considers so many federal cases that often end up at the U.S. Supreme Court, and because so many of its members have been appointed to the high court.
Senate Republican Leader Mitch McConnell said Halligan meets the "extraordinary circumstances" standard for a filibuster under a 2005 Senate agreement that allowed filibusters of judicial nominees only in extreme cases. McConnell complained about Halligan's legal positions on gun rights, detainee rights, and immigration and said she would bring an activist agenda to the court.
"In Ms. Halligan's view, the courts aren't so much a forum for the even-handed application of the law as a place where a judge can work out his or her own ideas of what society should look like," McConnell said on the Senate floor.
The four remaining Republican members of the so-called "Gang of 14" -- Sens. Lindsey Graham of South Carolina, Susan Collins of Maine, John McCain of Arizona, and Olympia Snowe of Maine -- all voted against allowing Halligan's name to come to a final vote.
Democrats defended Halligan as a "superbly qualified nominee," in the words of Sen. Patrick Leahy, D-Vermont, the Judiciary Committee chairman. Sen. Chuck Schumer, D-New York, called her a "moderate" and said Republicans have distorted her record.
Schumer said the decision by Republicans to filibuster Halligan means the 2005 Senate agreement, hammered out then by the Gang of 14, would be "null and void." He said it could lead to "chaos" as the Senate deals with judicial confirmations in the future, particularly those on the circuit court level.
Sen. Orrin Hatch, R-Utah, voted present instead of yes or no. Sen. Lisa Murkowski, R-Alaska, was the only senator to cross party lines when she voted in favor of moving the nomination forward.
The president also criticized Republicans for blocking 20 other nominees to the federal bench, half of whom would fill seats that have been labeled "judicial emergencies" because of rising caseloads and shortages of judges to handle them.
"I urge Senate Republicans to end this pattern of partisan obstructionism and confirm Ms. Halligan and the other judges they have blocked for purely partisan reasons," said Obama.
At least two dozen liberal advocacy groups slammed the GOP strategy, many warning a new era of partisan sniping over judicial nominees was beginning.
This is the second Republican-led filibuster of an Obama judicial nominee. Former law professor Goodwin Liu was blocked in May from serving on the 9th Circuit U.S. Court of Appeals in San Francisco. He was later named to the California Supreme Court.
Republicans had been criticized for delaying floor votes on many nominees in the president's first two years in office, but the White House, too, has come under fire for not moving quickly to fill growing bench vacancies. The president's two Supreme Court choices -- Sonia Sotomayor and Elena Kagan -- received relatively swift consideration.
Some moderates from both parties have long lamented threats of delays and filibuster attempts of most presidential appointments. They say ongoing unfilled vacancies have created a crisis in many federal courts, with bulging dockets being handled by too few judges.
Among the current Supreme Court, four members -- Chief Justice John Roberts and Justices Antonin Scalia, Clarence Thomas, and Ruth Bader Ginsburg -- served on the D.C. Circuit before being named to the high court.
CNN's Bill Mears contributed to this report.