WASHINGTON (Reuters) - 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.
Now Democratic President Barack Obama, putting together his team for his second term, is poised to choose the intensely independent thinker to run the Pentagon. If Hagel is confirmed by the Senate, he will have to oversee the withdrawal of U.S. troops from another war zone - Afghanistan - and grapple with spending cuts.
The formal announcement of Hagel's nomination could come as early as Monday, Democratic Party sources said.
A social conservative and strong internationalist who co-chaired John McCain's failed Republican presidential campaign back in 2000, Hagel might seem an unlikely pick for Obama's Secretary of Defense, were it not for his opposition to the Iraq war launched by former President George W. Bush. That war was the issue on which Obama also rose to national prominence.
Four years ago, Obama said Iraq was not the only matter where he held similar views with Hagel, a decorated Vietnam veteran 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 taking Hagel with him on a tour of Iraq.
Since his name emerged last year as a candidate for the Pentagon, some Republicans contend that Hagel has at times opposed Israel's interests. His critics note he voted against U.S. sanctions on Iran and made disparaging remarks about the influence of what he called a "Jewish lobby" in Washington.
Hagel has also been critical of the size of the American military, telling the Financial Times 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, but also serves as co-chairman of the President's Intelligence Advisory Board and 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 the debt-ceiling debate.
In 2012 he endorsed a Democrat 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 the years of Republican President Bush.
AS A SENATOR, CLASHED WITH OTHER REPUBLICANS
While he was in the Senate as a senior 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 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 fought, but later decided was wrong. His stance put him at odds with his fellow Republican maverick, McCain, and Hagel was pilloried by other Republicans.
Former Vice President Dick Cheney 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."
In 2008, Hagel did not make a public endorsement in the presidential race, but his wife Lilibet endorsed Obama and sat with Obama's wife Michelle during the last presidential debate.
Hagel skipped the 2008 Republican convention to travel to Central and South America. Then he further irked Republicans 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 was once considered a contender for the 2008 presidency himself, and there was speculation he would join New York Mayor Michael Bloomberg on an independent ticket. Instead he said in September 2007 that he was dropping out of politics and retiring from the Senate when his term ended in 2008.
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. (Reporting By Susan Cornwell; Editing by David Brunnstrom)