Republicans on the Senate Judiciary Committee unanimously endorsed Sen. Arlen Specter (R-Pa.) as the committee's new chairman yesterday, overriding complaints from conservative activists that he might try to block antiabortion nominees to the Supreme Court.

Specter got his colleagues' blessing after he drafted a statement -- and strengthened it during negotiations with GOP leaders and committee Republicans -- pledging prompt hearings and votes on President Bush's judicial nominees. He also vowed to try to curtail Democratic filibusters against judicial choices and held the door open to the possibility of a rule change to ban such filibusters, although he did not endorse it.

His statement followed an extraordinary two weeks during which Specter took the highly unusual step of waging a public fight -- including more than 30 broadcast appearances as well as countless conversations with colleagues -- to secure a chairmanship that normally would have gone to him without question because of his 24 years of seniority on the panel. Rarely, if ever, has a chairman-to-be had to issue such a public statement to win the support of his colleagues.

The ordeal demonstrated the clout of conservative groups in the GOP but also underscored its limits in a chamber that values its traditions and personal relationships.

While official votes by committee Republicans and the full Senate GOP caucus will not occur until after the new Congress convenes in January, the endorsement appeared to ensure Specter's elevation to the powerful post at a time when the committee may consider one or more nominees to the Supreme Court as well as scores of choices for lower federal courts.

Asked if Specter's selection as chairman was now a "done deal," the outgoing Judiciary Committee chairman, Orrin G. Hatch (R-Utah), responded, "It's a done deal, yes, a done deal."

Hatch, who was joined by an obviously relieved Specter and most other committee Republicans at a midafternoon news conference, said he was speaking for all nine GOP committee members in saying they were satisfied with Specter's assurances.

"We're happy with the statement that Arlen has made," said Hatch, who is leaving the post because of the Senate GOP's six-year term limits for chairmen. "We're happy with Arlen Specter and his commitment. And we're happy with his service. He's been supporting the president's judges."

In his statement, Specter reiterated -- and formalized -- many of the assurances he offered colleagues after he questioned at a Nov. 3 news conference whether a strongly antiabortion Supreme Court nominee could get confirmed by the Senate. He said he was referring only to Democratic filibusters, but critics interpreted his comment as suggesting a litmus test on abortion rights for nominees. Conservative groups flooded the Capitol with phone calls and e-mails urging that Specter be passed over for the chairmanship.

Majority Leader Bill Frist (R-Tenn.) and others demanded further clarification and commitments from Specter, and most Republicans on the Judiciary Committee withheld public support for him until yesterday, with some of them insisting on a strong public statement from Specter before they would endorse him.

"I have not and would not use a litmus test to deny confirmation to pro-life nominees," Specter said in the carefully worded one-page statement, noting that he has supported antiabortion nominees to the court and helped lead the fight to confirm Justice Clarence Thomas in 1991.

"I have assured the president that I would give his nominees quick committee hearings and early committee votes so floor action could be promptly scheduled," he said. "I have voted for all of President Bush's judicial nominees in committee and on the floor, and I have no reason to believe that I'll be unable to support any individual President Bush finds worthy of nomination."

Specter said he would "use my best efforts to stop any future filibusters" and hoped such confrontations could be avoided because of the four-seat GOP gain in the Senate in the Nov. 2 elections and what he described as "voter dissatisfaction with Democratic filibusters."

"If a rule change is necessary to avoid filibusters, there are relevant recent precedents to secure rules changes with 51 votes," he said.

This was an oblique reference to a parliamentary maneuver under consideration by GOP leaders under which filibusters on judicial nominations would be declared unconstitutional, subject to a simple majority of Senate votes -- or 51 of the 55-member majority that Republicans will have in the new Congress.

Democrats have said this "nuclear option" would destroy all remnants of bipartisan comity in the chamber, but many Republicans have said it may be necessary if Democrats continue to block Bush nominations. In the current Congress, Democrats have blocked 10 of Bush's most conservative nominees to federal appeals courts while allowing confirmation of 200 other district and appellate nominees.

Specter also promised to consult with colleagues on the committee's legislative agenda, including lawsuit reform, and said he would not bottle up any bills or constitutional amendments that he opposes.

The reaction from conservative groups was cool. "Specter's word will be tested through his leadership on the Judiciary Committee . . . We intend to hold him to these commitments," said Tony Perkins, president of the Family Research Council. Further commitments are needed, said Concerned Women for America, including a pledge to fight vigorously for Thomas if he is nominated for chief justice.

Sen. Arlen Specter (R-Pa.) lobbied his colleagues for the chairmanship of the Judiciary Committee.