So why did President Obama choose Chuck Hagel to be his new defense secretary?
First, Hagel is Obama's kind of Republican. The former senator from Nebraska is a realist and pragmatist who hasn't been afraid to buck the orthodoxy of his chosen party, for instance when Hagel opposed the Iraq War.
In that way, he's a lot like Obama, another foreign policy and national security realist who has been willing at times to upset those in his own party. The use of drone strikes against alleged terrorist targets — some of whom have been U.S. citizens — has angered any number of Democrats.
In his remarks Monday afternoon, the president noted that he prized Hagel's independence of mind and willingness to take politically unpopular positions. That's just what you would expect to hear from a president who has made Abraham Lincoln's "team of rivals" approach to choosing a Cabinet his White House touchstone.
Second, Obama also clearly is very comfortable personally with Hagel, whom the president bonded with during his short U.S. Senate career. As Obama reminded his audience, he and the Nebraskan traveled together as senators to the Middle East.
"I think it is not simply the fact that Sen. Hagel is qualified, but the trust the president places in him," says Anthony Cordesman, a national security analyst at the Center for Strategic and International Studies. "This is somebody who has been very thoughtful. He is not someone who takes ideological stands. He has a real military background both in dealing with war and then dealing with" its aftermath, since Hagel isn't just a Vietnam veteran but a former Veterans Administration official.
Besides befriending Obama when the Illinoisan was a rock-star senator, Hagel also had long-standing Senate friendships with two other senators who have played significant roles in Obama's ascent and presidency, Vice President Biden (the former Delaware senator) and Secretary of State-designate John Kerry (the senior senator from Massachusetts).
Biden, Kerry and Hagel have shared much together, including some anxious moments in 2008 when during a trip to Afghanistan, a snowstorm forced their helicopter to make an emergency mountaintop landing.
Thus, Hagel's addition to the Obama administration would put four men with close ties from the Senate at the center of the nation's foreign policy and national security policymaking. That could have real benefits, given the imperative that foreign policy and national security mesh. Worth noting is that the three Democrats each ran for president while Hagel, the Republican, toyed with the idea but ultimately decided against it.
Third, picking Hagel gives Obama the chance to assert his presidential prerogative to choose whom he wants for his Cabinet.
Senate Republicans successfully forced Obama to rethink U.N. Ambassador Susan Rice as a potential secretary of state after warning that they were prepared to wage a no-holds-barred confirmation battle if he nominated her to succeed Hillary Clinton. Rice took her name out of consideration, and that storm ended.
By nominating Hagel, Obama gets to frame the fight with Senate Republicans in ways more favorable to him. In choosing a Republican who as a senator occasionally strayed from GOP talking points, Obama puts Republicans in a trickier position.
Senate Republicans could reject the president's attempt at bipartisanship represented by his choice of Hagel. But it wouldn't make them look good in the eyes of the majority of voters who tell pollsters that they want Washington politicians to cross party lines to get things done.
Hagel was actually on Obama's short list in 2009 for defense secretary, but the president wound up sticking with Bush administration holdover Robert Gates.
Fourth, Obama is obviously not worried about charges that Hagel is anti-gay or anti-Israel.
To a large extent, Obama inoculated himself against the anti-Hagel allegations through his own policies. He signed into law the end of the military's "don't ask, don't tell" ban on gays, lesbians, bisexuals and transgendered people openly serving in the armed services; finally said he supported marriage equality; and ordered his administration to not enforce the Defense of Marriage Act.
For his part, Hagel apologized for comments he made in the 1990s in which he questioned whether an "aggressively" gay ambassadorial nominee would be an appropriate representative of the U.S., an apology that's been accepted by some gay groups.
Obama also very likely isn't too worried about allegations sticking that Hagel is anti-Israel, for similar reasons. Those charges are based in part on Hagel's past use of the term "Jewish lobby."
Hagel has apologized for that, too. And he can probably count on getting the benefit of the doubt from many who are pro-Israel. Jewish voters chose Obama by a wide margin in the 2012 election, giving him about 70 percent of their votes, a share similar to what he received in 2008.
Fifth, Hagel's two terms in the Senate, his success as a businessman, his roles as a VA official and as the head of the USO, uniquely position him to oversee a Pentagon facing spending cuts as the federal government grapples with reducing its debt and deficits.
Cordesman, who would talk informally with Hagel when the two men, who lived on Capitol Hill, would bump into each other, says this is "somebody who listens and consults. He will be very careful to get opinions from the military and civilians and from outside. Given the complexity of the issues involved, that's critical. What's equally critical is he can speak to people on the foreign policy side because in today's world there's no clear separation between security and foreign policy."