WASHINGTON — Senate Republicans on Thursday blocked President Obama’s picks for a powerful federal court and a housing regulatory agency, prompting Democrats to threaten curtailing the GOP’s ability to derail nominations.
‘‘Something has to change, and I hope we can make the changes necessary through cooperation,’’ Senate majority leader Harry Reid, Democrat of Nevada, said after the votes.
In a setback for the president, Republicans derailed his picks of Patricia Millett to become a judge on the US Court of Appeals for the District of Columbia Circuit and Representative Melvin Watt, Democrat of North Carolina, to lead the Federal Housing Finance Agency. The Senate voted 55-38 to end the delays against Millett and 56-42 to end the blockade against Watt — falling shy each time of the 60 votes Democrats needed to prevail.
The defeats immediately subjected Democratic leaders to pressure from liberal groups and newer Democratic senators to change Senate rules that let the minority party — currently Republicans — force the majority to muster 60 votes on controversial nominations, instead of a simple majority.
Within minutes, a coalition of Democratic-leaning groups including the Alliance for Justice, the Communications Workers of America, Common Cause, and the Sierra Club issued a statement saying ‘‘Democrats must be prepared to change the Senate rules.’’
Said freshman Senator Chris Murphy of Connecticut: ‘‘The conversation on rules changes can’t come fast enough for me.’’ He called the GOP procedural hurdles ‘‘a government shutdown by another tactic.’’
No. 2 Senate GOP leader John Cornyn of Texas said he doubted Democrats would act on their threats, which they had been hinting at for days. He said if Democrats change the rules and Republicans win the White House and Senate, ‘‘Then we could confirm another Scalia, another Thomas with 51 votes,’’ a reference to conservative Supreme Court Justices Antonin Scalia and Clarence Thomas. ‘‘So I think they need to think twice, and I think they understand that.’’
Some senior Democrats have opposed limiting minority party power in the Senate, saying they would regret it whenever the GOP gains control.
The Millett defeat was particularly stinging for Democrats.
The D.C. circuit court issues decisions on White House and federal agency actions and is considered second in power only to the Supreme Court. Millett’s confirmation would have produced a 5-4 tilt among that court’s judges toward those chosen by Democratic presidents, and the appointments are lifetime positions.
Millett, now a prominent private attorney, was an assistant solicitor general under both Bill Clinton and George W. Bush, representing those administrations before the Supreme Court. She has argued 32 cases before the highest court.
Republicans said the D.C. circuit court’s workload was lighter than other districts and didn’t merit filling any of its three vacancies. They also said Democrats want to turn that court into a rubber stamp for Obama administration policies.
‘‘This is the court that can rule for or against the executive orders of this administration. We need to maintain checks and balances of the government,’’ said Senator Charles Grassley, Republican of Iowa.
Democrats say caseload totals for the D.C. circuit are close to its 10-year average. They also say that when the GOP held the White House, Republicans voted to fill the court’s ninth seat with John Roberts, now the US chief justice.
Obama has nominated attorney Cornelia ‘‘Nina’’ Pillard and US District Judge Robert Wilkins to bring the court to its full strength, nominations that have yet to reach the full Senate.
Last July, Democrats abandoned a threat to change Senate rules after Republicans agreed to supply enough votes for approval of several Obama nominations.
Those included his choices to head the Environmental Protection Agency and the Labor Department.
Reid switched his vote to ‘‘no’’ on both roll calls on Thursday, a procedural move that gives him the right to force fresh votes on both nominees. He said the Senate would reconsider both votes ‘‘in the very near future.’’
The Federal Housing Finance Agency oversees government-owned mortgage giants Fannie Mae and Freddie Mac, which own or back about half of all US mortgages.
Watt is a 21-year veteran of the House and its Financial Services committee. Democrats have praised his pro-consumer record. He has won support from the National Association of Realtors and the National Association of Home Builders.
Watt faced opposition from Republicans who said he was short on technical expertise needed to oversee Fannie and Freddie, and from conservative groups that criticized his support for federal intervention in the troubled housing industry.