The silver-haired Virginian with courtly manners is a throwback to a forgotten era of congressional comity. But as he leads the Senate's inquiry into abuse of Iraqi prisoners, Armed Services Committee Chairman John W. Warner (R-Va.) also shows another side: a penchant for bucking his party, taking heat and surviving.

Warner says his committee has a "solemn responsibility" to discover what went wrong and to "make sure it never, never happens again." But some conservatives are angry about the high-profile televised hearings, saying the prisoner-abuse issue is overblown and threatens to undermine the United States' primary mission in Iraq.

As a result, the 77-year-old Virginian finds himself in an uncomfortable but familiar position: more at odds with the right flank of his own party on some critical issues than he is with Democrats.

"I think he should stop the hearings at this point; we've heard enough," said Sen. James M. Inhofe (R-Okla.), a committee member. "We have a war to win, and we need to keep our talents concentrated on winning the war as opposed to prisoner treatment."

House Armed Services Committee Chairman Duncan Hunter (R-Calif.) complained that Warner and other Senate members have become "mesmerized by cameras." Defense Secretary Donald H. Rumsfeld was irked when Warner, in a departure from normal committee practice, decided to put all abuse-inquiry witnesses -- including the secretary -- under oath, according to Senate sources.

But Warner shows no signs of backing off, arguing that the country wants and deserves a vigorous examination of the sexual humiliation, physical abuse and torture of Iraqi prisoners at the Abu Ghraib prison. He has held three televised hearings this month to question top Pentagon officials and military commanders -- two more televised sessions than the House has allowed -- and he is planning more.

Friends say Warner -- a sailor in World War II, a Marine during the Korean War and secretary of the Navy before he came to the Senate in 1979 -- is motivated by a strong belief that the reputations of both the military and the Senate are at stake unless they get to the bottom of the scandal. "To do otherwise would be contradictory to everything he has experienced in his professional life," said committee member John McCain (R-Ariz.). Besides, McCain added, "it would be incredibly stupid politically."

Throughout the hearings, Warner has been respectful of Pentagon officials but no cheerleader. He praised Rumsfeld's testimony as "strong and in every sense heartfelt" and reaffirmed his support for the secretary. Yet he has defied pressure from Hunter and other Republicans to curtail the public investigation. And he occasionally has posed questions that have evoked important information, as when he asked of Maj. Gen. Antonio M. Taguba, chief author of a report on prisoner abuse: "In simple words -- your own soldier's language -- how did this happen?"

Taguba replied: "Failure in leadership, sir, from the brigade commander on down. Lack of discipline, no training whatsoever and no supervision. Supervisory omission was rampant."

Warner's style of questioning at times has been overshadowed by the more aggressive probing and criticism of other senators on the committee, including Republicans Susan Collins (Maine), Lindsey O. Graham (S.C.) and McCain. They have been more aggressive than Warner in demanding information from the Pentagon.

Some congressional staff members complained that Warner moved slowly in getting the Defense Department to supply a complete copy of the Taguba report. Only after six senators drafted a letter to Warner demanding that he obtain such a copy did Warner extract a promise from the Pentagon that it would be supplied -- by an unspecified date.

Still, Warner's pursuit of the issue has the backing of most Armed Services members as well as Senate Majority Leader Bill Frist (Tenn.), though he has infuriated some conservatives. Sen. John Cornyn (R-Tex.), another committee member, has expressed concern that the hearing may be "a real distraction from trying to win the war, especially at this most fragile time." House Majority Leader Tom DeLay (Tex.) also suggested a lower profile for the prisoner-abuse issue, saying, "We should not allow it to distract us from the war at hand."

In contrast, both Sen. Carl M. Levin (Mich.), ranking Democrat on the Senate committee, and Sen. Edward M. Kennedy (D-Mass.), a senior member of the panel, applaud the course that Warner has taken. "I think he deserves a lot of credit for standing up to the more excitable elements of his party who want to put a halt to the hearings," Kennedy said. "They have been useful and informative."

In a recent interview, Warner brushed off the GOP criticism and seemed to take pride in his independence. He confessed to being a bit of a "maverick" in his recent commencement address at the University of Virginia. "Sometimes you have to say politics be damned," he added.

Warner, the son of a World War I field surgeon, won election to the Senate in 1978 after his state party's first choice, Richard D. Obenshain, was killed in a plane crash.

Warner is generally a loyalist and votes with a majority of Republicans on nearly all key issues, including President Bush's Iraq policies. He is also a conciliator within the party. "When things are getting pretty tense, and everyone is getting agitated, he has a very calming demeanor of leadership," said Sen. George Allen (R-Va.).

His military experience and familiarity with defense issues helped him move from semi-obscurity in his early years in the Senate (when he was known mainly as the husband of actress Elizabeth Taylor) to the forefront of defense policy deliberations on Capitol Hill. "Senator Warner is a military guy through and through. He volunteered twice, served in the armed forces twice -- that's twice more than a lot of members," said Rep. Thomas M. Davis III (R-Va.).

It is Warner's periodic departures from GOP orthodoxy -- on issues such as abortion, guns and Republicans' nomination of conservative hero Oliver L. North for Virginia's other Senate seat in 1994 -- that infuriate Warner's critics.

He voted against conservative Supreme Court nominee Robert H. Bork in 1987 and in 1993 repudiated Virginia GOP lieutenant governor nominee Michael P. Farris, a favorite of the party's right. He has voted for some abortion rights positions and against others, and he was recently among a small minority of Republicans to vote to extend the partial ban on assault weapons.

Warner played a key behind-the-scenes role in replacing former Republican leader Trent Lott (Miss.) with Frist in 2002 after Lott made remarks that many considered racially insensitive. Most recently, he angered some Virginia Republicans by endorsing the tax-hike push by Gov. Mark D. Warner (D).

His opposition to North stirred the most controversy. Reflecting a prevalent view in the military establishment that the former Marine lieutenant colonel and Iran-contra figure was a rogue officer, Warner recruited another Republican to challenge North as an independent. Sen. Charles S. Robb (D) was reelected as a result. Conservatives later tried to deny Warner the GOP nomination for reelection, but Warner outmaneuvered them.

Despite the recurrent furors he has created within the Virginia GOP, Warner coasted to an easy victory when he ran for a fifth term in 2002 and is generally regarded as the most popular politician in the state. He says he would like to run again in 2008 but will wait until later to decide. Among possible GOP candidates to succeed him are several House members, including Davis, a close friend of Warner's. Former governor James S. Gilmore III, who has said he will be a candidate for public office again some day, is another possible candidate.

Sen. John F. Kerry (Mass.), the president's Democratic challenger, has mentioned Warner as a possible defense secretary, and there has been speculation that he may be in Bush's Cabinet list for a second term. But Warner dismissed such talk, saying running the Pentagon is a job for a younger person.

Some see Warner's intervention against North and his outrage over the prisoner abuse as dual reflections of his devotion to the military.

Warner puts it in more personal terms. He went through both undergraduate and law school under the G.I. Bill of Rights and feels he owes the military for everything he has become. "I have a tremendous obligation to the military," he said.

Staff writer R. Jeffrey Smith contributed to this report.

John Warner has described himself as a maverick.Majority Leader Bill Frist (Tenn.), left, has backed Warner's hearings on the Abu Ghraib prison scandal. But conservatives have voiced objections.