GOP members expressed concern that her views were too “extreme” on gun control, abortion and terrorist detention, but Democrats said those were the views of her clients, not Halligan's.

Senate Minority Leader Mitch McConnellAddison (Mitch) Mitchell McConnellGun proposal picks up GOP support Children’s health-care bill faces new obstacles Dems see Trump as potential ally on gun reform MORE (R-Ky.) said Halligan would be an “activist judge.”

“Because of her record of activism, giving Ms. Halligan a lifetime appointment on the D.C. circuit is a bridge too far,” McConnell said.

Senate Judiciary Committee Chairman Patrick LeahyPatrick Joseph LeahyOvernight Regulation: Massachusetts AG sues Equifax | Trump weighs easing rules on gun exports | EPA nominee to fight worker safety rule in court Trump to ease rules on gun exports: report Overnight Defense: Senate passes 0B defense bill | 3,000 US troops heading to Afghanistan | Two more Navy officials fired over ship collisions MORE (D-Vt.) said that those "misrepresenting" Halligan as an “ideological crusader” were wrong.

Democrats said Republicans have set a bad precedent, since during rules negotiations just two months ago they promised not to block nominations unless there were “extraordinary circumstances.”

“If this is an indication of where we’re headed, we need to revisit the rules again,” Sen. Dick DurbinRichard (Dick) Joseph DurbinGun proposal picks up GOP support Durbin: I had 'nothing to do' with Curbelo snub Republicans jockey for position on immigration MORE (D-Ill.) said.

Schumer said that Republicans failed to prove “extraordinary circumstances” in their objection to Halligan.

“The desire to actually filibuster Caitlin Halligan is really causing a lot of consternation on our side. Clearly this is a judge that deserves a vote,” Sen. Charles SchumerCharles (Chuck) Ellis SchumerOvernight Health Care: Schumer calls for tying ObamaCare fix to children's health insurance | Puerto Rico's water woes worsen | Dems plead for nursing home residents' right to sue Crying on TV doesn't qualify Kimmel to set nation's gun agenda Trump knocks ‘fake’ news coverage of his trip to Puerto Rico MORE (D-N.Y.) said. “Wearing the wrong color tie or blouse could be an ‘extraordinary circumstance.’ ”

Senate Majority Leader Harry ReidHarry ReidChris Murphy’s profile rises with gun tragedies Republicans are headed for a disappointing end to their year in power Obama's HHS secretary could testify in Menendez trial MORE (D-Nev.) called the GOP filibuster “naked partisanship.”

“If a truly exceptional candidate such as Caitlin Halligan isn’t qualified to be a judge in the United States of America, I don’t know who is,” Reid said.

Reid voted against the cloture motion as a procedural move so that he can later bring up Halligan's nomination again.

Republicans pointed to a legal briefing she signed that questioned the legality of detaining suspected terrorist as enemy combatants. 

“We have before us one of the most activist nominees,” Sen. Orrin HatchOrrin Grant HatchGOP eyes limits on investor tax break Children’s health-care bill faces new obstacles Overnight Finance: White House requests B for disaster relief | Ex-Equifax chief grilled over stock sales | House panel approves B for border wall | Tax plan puts swing-state Republicans in tough spot MORE (R-Utah) said. “She has an activist judicial philosophy and is simply not qualified to sit on the judicial bench.”