President Obama slammed Senate Republicans on Wednesday for again filibustering the nomination of Caitlin Halligan to the important D.C. Circuit Court of Appeals.

Senate Democrats were unable to overcome a GOP filibuster on Wednesday in a 51-41 vote that for the second time blocked Halligan's appointment as a U.S. circuit judge for the District of Columbia. Democrats needed 60 votes to advance her nomination.

Obama blasted the vote, saying it highlighted a "Republican pattern of obstruction" in a statement released by the White House.

"In the past, filibusters of judicial nominations required 'extraordinary circumstances'; and a Republican Senator who was part of this agreement articulated that only an ethics or qualification issue – not ideology – would qualify," Obama said. 

"Ms. Halligan has always practiced law with the highest ethical ideals, and her qualifications are beyond question," he added. "Furthermore, her career in public service and as a law enforcement lawyer, serving the citizens of New York, is well within the mainstream."

On Tuesday, White House spokesman Jay Carney noted that the D.C. circuit court now had four vacancies, arguing that "the court has never been this understaffed in its history and the caseload has increased almost 15 percent since 2011."

"This is a problem that needs to be resolved for the sake of our judicial system, for the sake of a carrying out of justice in our country in an expedited and deliberate manner," Carney said.

The White House had expressed muted optimism that Halligan's nomination would be allowed to proceed to an up-or-down confirmation vote.

"We have seen some positive signs of late that perhaps the logjam is beginning to break on Capitol Hill when it comes to confirmation of judges, and we certainly hope that the spirit that informs that change, modest as it has been, will inform the vote the Senate takes on Caitlin Halligan," Carney said Tuesday.

But Republicans said Wednesday that Halligan's stances on hot-button issues like gun control and abortion were too "extreme" to avoid filibuster.

“Because of her record of activism, giving Ms. Halligan a lifetime appointment on the D.C. circuit is a bridge too far,” Senate Minority Leader Mitch McConnellAddison (Mitch) Mitchell McConnellGiuliani: White House wants briefing on classified meeting over Russia probe GOP senators introduce Trump's plan to claw back billion in spending The Hill's 12:30 Report — Sponsored by Delta Air Lines — Trump now says Korea summit could still happen June 12 MORE (R-Ky.) said.

Obama is the only president yet to place a nominee on the D.C. circuit. The court is considered highly influential, often handling legal challenges involving federal agencies and executive actions. Four sitting Supreme Court justices, including Chief Justice John Roberts, served on the court earlier in their careers.

Democrats have accused Republicans of willfully delaying Obama’s judicial appointments and holding them to a higher standard for confirmation than was the case for past presidents.

Senate Judiciary Committee Chairman Patrick LeahyPatrick Joseph LeahyMcConnell sets 'minibus' strategy for 2019 spending Dem senator mocks Pruitt over alleged security threats: 'Nobody even knows who you are' Pruitt tells senators: ‘I share your concerns about some of these decisions’ MORE (D-Vt.) has pressed GOP lawmakers to move quickly to fill judicial vacancies on the nation’s federal courts.

“President Obama has nominated qualified, mainstream lawyers, and the Senate should consider them in regular order, without unnecessary delays,” Leahy said in a statement last week heralding the confirmation of William Kayatta, the first judicial pick approved by the upper chamber this year.  “That is what we had done for as long as I have served in the Senate, whether the nominations came from a Democratic or a Republican president.” 

-Ramsey Cox contributed.