Ordinarily, Sen. Rick Santorum (search) might figure to be Sen. Arlen Specter's (search) most public of allies in a fierce and ultimately successful battle for the chairmanship of the Senate Judiciary Committee (search), one Pennsylvania Republican aiding another in a classic Capitol power struggle.

But while home state concerns prodded Santorum to help Specter, a moderate who supports abortion rights, his own budding national constituency of conservatives pulled angrily in the other direction. The result was uncharacteristic reticence on the part of the Senate's third-ranking Republican, a 46-year-old, second-term lawmaker who seems to relish political combat and may harbor national ambitions as well.

"I don't want to usurp the power of the committee by making a recommendation one way or the other," he told reporters Wednesday. "This is the committee's decision," he added of the panel that reviews President Bush's appointments to the federal courts.

Nor did Santorum attend a key leadership meeting this week at which Specter underwent an extraordinary vetting.

Nor was he in evidence Thursday when Specter won his battle after issuing an extraordinary public pledge designed to satisfy conservative skeptics. "I have assured the president that I would give his nominees quick committee hearings and early committee votes," regardless of their views on abortion, Specter said.

Moments later, perhaps inadvertently, he framed Santorum's political dilemma. Asked whether his fellow Pennsylvanian had helped him gain his lifelong political goal, Specter quickly said, "Yes." Then, catching himself in mid-sentence, he added: "Well. It may get him into trouble if I say yes. Let him speak for himself."

Santorum's office first initiated plans for an interview on the chairmanship controversy, then scrapped them.

His attitude seemed different two weeks ago, when the controversy first flared. That was when Specter, fresh from a home state re-election victory, said anti-abortion nominees to the Supreme Court would likely find it difficult to win Senate confirmation.

"I look forward to working with Senator Specter to guarantee that every judicial nominee put forth by President Bush has an up-or-down vote on the floor of the United States Senate," Santorum said in a statement issued before he stepped back from his public role in the controversy.

But while Santorum was telling reporters earlier this week he wasn't taking sides, other Republicans said that came as news to them. "Santorum has been supportive of Specter," Sen. Jeff Sessions of Alabama said, an assessment that other senators confirmed on condition of anonymity.

Outside the Senate, Santorum's initial tilt infuriated some conservatives, still angry that he sided with Specter against a primary challenger, conservative Rep. Pat Toomey, last spring. He did so after reassuring his supporters that whatever Specter's personal views on abortion, he had never applied a litmus test to appointments to the court in the past, and had pledged not to do so in the future.

"I don't expect Senator Santorum to support (Specter)," said Nancy Staible, Pennsylvania state director of Concerned Women for America, a conservative organization that claims 10,000 Pennsylvania members. She said she would "have to reconsider my support" for Santorum, whom she said she has known since before he came to Congress in 1990.

"I think Santorum has really injured himself here," said the Rev. Patrick Mahoney, head of the Christian Defense Coalition. "I view Senator Santorum as trying to find refuge in a political firestorm, and he's doing what is so common among Washington politicians, which is ... sticking his finger up and seeing which way the wind is going to blow."

Santorum's term expires in 2006, and Mahoney said a group of conservative activists have scheduled a weekend meeting in Pennsylvania to discuss the feasibility of mounting a primary challenge to him, possibly by appealing to Toomey to run. Toomey's spokesman, Joe Sterns, said he had no knowledge of any such plan.

"They've been mad for quite awhile, and I don't think the senator has done any outreach in the conservative wing of the party," said Bill Green, a Republican political consultant in Pittsburgh.

"He's on the ballot in two years and I'm sure the Santorum people are going to say, `Where else are those people going to go, they're always going to be with us.' But I don't think he wants to go through a baptism of fire," said Green, who added he believes the senator has White House ambitions for 2008.

Santorum stoked that impression at the Republican National Convention in New York last summer, when he visited delegates from New Hampshire, the state with the first presidential primary.

He will be only 50 when the next presidential election occurs, and Santorum has always given the impression of being a politician in a hurry. Elected to the House in 1990, he served two terms before winning his Senate seat in the Republican landslide year of 1994. Even before he began his climb up the leadership ladder and cemented his standing as a prominent anti-abortion senator, he led a newcomer's charge against Sen. Mark Hatfield. A moderate who was chairman of the Appropriations Committee. Hatfield had cast the deciding vote against a balanced budget amendment to the constitution, a core party issue.

Santorum was vocal then, playing a public role in calling for a meeting to discuss Hatfield's fitness for his chairmanship. Now, a dozen years and one committee controversy later, he sought to cloak his role in secrecy. An aide said he did not plan to issue a statement noting Specter's triumph.