From his lonely position as an early Republican critic of the Iraq war, former Nebraska Senator Chuck Hagel sometimes lectured his more timid Senate colleagues. "If you wanted a safe job, go sell shoes," he told them.
President Barack Obama's nominee for defense secretary began a Senate confirmation process on Thursday that revived the contentious relations the fiercely independent Vietnam war veteran had with fellow Republicans over his political career.
"I'm proud of my record," Hagel declared before the Armed Services Committee. "I'm on the record on many issues. But no one individual vote, no one individual quote, no one individual statement defines me, my beliefs or my record."
A social conservative and strong internationalist who co-chaired John McCain's failed Republican presidential campaign in 2000, Hagel might have seemed an unlikely pick for Obama were it not for his opposition to the Iraq war launched in 2003 by former President George W. Bush, a Republican.
Opposing that war was the issue on which Democrat Obama also rose to national prominence and he has said that Iraq was not the only matter where he held similar views with Hagel, who was also once touted as presidential material.
"He's a staunch Republican, but Chuck and I agree almost on every item of foreign policy," Obama said in August 2008, a month after joining Hagel on a tour of Iraq.
Hagel's detractors noted he had voted at times against U.S. sanctions on Iran, and said he had made disparaging remarks about the influence of what he called a "Jewish lobby" in Washington.
Hagel rejects the allegations, saying that he had always supported Israel, and if confirmed he would ensure America's military is prepared to strike Iran if necessary.
Hagel has also been critical of the size of the American military, saying in an interview in 2011 that the Defense Department was "bloated" and needed "to be pared down."
Hagel served two terms in the Senate, representing the state of Nebraska, and left in 2008. He is now a professor at Georgetown University in Washington D.C.. He also serves as co-chairman of the President's Intelligence Advisory Board and is a member of the Secretary of Defense's Policy Board.
Since he left the Senate, Hagel has been a big critic of his own party. He told the Financial Times in 2011 that he was "disgusted" by the "irresponsible actions" of Republicans during a fractious debate over raising the U.S. debt-ceiling in 2011.
Last year he endorsed a Democratic candidate for Senate from Nebraska - former Senator Bob Kerrey - instead of Republican Deb Fischer, who won.
Hagel would not be the first Republican to serve Obama as Pentagon chief. Bob Gates, Obama's first defense secretary, was a holdover from his predecessor George Bush.
CLASHES WITH FELLOW REPUBLICANS
While he was in the Senate as a member of the Foreign Relations, Banking, and Intelligence Committees, Hagel often clashed with his party's leaders on foreign and defense policy.
He co-sponsored legislation to ease U.S. trade restrictions with Cuba, and at times voted against trade sanctions on Iran and Libya.
In 2002 Hagel said the U.S. should try to improve relations with the countries Bush had branded an "axis of evil" - Iraq, Iran, and North Korea.
The same year, when Hagel expressed doubts about the Bush administration's buildup to war in Iraq, the conservative Weekly Standard magazine branded him part of an "axis of appeasement." But Hagel did vote to give the president the authority to carry out the March 2003 invasion.
Later Hagel said he regretted that vote and became a persistent critic of the conflict. In January 2007, he was the only Republican on the Senate Foreign Relations Committee to support a non-binding measure that criticized Bush's decision to send more troops to Iraq.
Hagel told senators they must take a stand on "the most divisive issue in the country since Vietnam," a war in which he had fought, but later decided was wrong. His stance put him at odds with McCain, who also has a reputation as a maverick, and Hagel was pilloried by other Republicans.
Bush's vice president Dick Cheney reflected the view of many in his party when he told Newsweek: "I believe firmly in Ronald Reagan's 11th Commandment: thou shalt not speak ill of a fellow Republican. But it's very hard sometimes to adhere to that where Chuck Hagel is involved."
Hagel did not make a public endorsement in the 2008 presidential race, but his wife Lilibet endorsed Obama and sat with Obama's wife Michelle during a presidential debate with McCain.
Hagel skipped the 2008 Republican convention, an important pre-election event, and further irked his party by telling the Omaha World-Herald newspaper that it was a "stretch" to say McCain's running mate Sarah Palin would be qualified to be president.
He had once been considered a contender for the 2008 presidency himself. Instead he said in September 2007 that he was dropping out of politics and retiring from the Senate when his term ended the following year.
Born in 1946, Hagel grew up in Nebraska as the oldest of four boys, and made a fortune by launching a cellphone company in the 1980s. His father was also a military man, a World War II veteran who died of a heart attack when Chuck was 16.
Hagel and his younger brother Tom volunteered for Vietnam, and Hagel saved Tom's life there by pulling him out of a burning vehicle.
In the early 1980s, when Ronald Reagan was president, Hagel served as deputy administrator of the Veterans Administration. (Reporting By Susan Cornwell; Editing by David Storey)