Former Senator Chuck Hagel, President Barack Obama's nominee for Secretary of Defense, testifies during his confirmation hearing before the Senate Armed Services Committee on Capitol Hill in Washington, D.C., on Jan. 31, 2013. To hear Chuck Hagel's detractors tell it, he's a corrupt, anti-woman, anti-gay, anti-Israel, Iranian-loving, Castro-cuddling chicken-hawk who will hide behind his two Vietnam Purple Hearts as he slashes the Pentagon budget and gets rid of America's nuclear arsenal. For all these reasons, they say, Hagel should not succeed Leon Panetta as Secretary of Defense. Outside groups have mounted one of the largest opposition efforts against a cabinet nominee in history. Not since Moveon.org's successful opposition to George W. Bush's pick of John Bolton as United Nations ambassador has a nominee undergone such scrutiny (Bolton, when blocked by the Senate, was eventually appointed to the job during congressional recess). And that was before the Citizens United case; Hagel has to contend with millions of dollars in negative television ads and mailers. Despite the blitz, Hagel's nomination looks likely to pass the Senate assuming he can survive Thursday's confirmation hearing in the Senate Armed Services Committee. Earlier this week, Senator Dick Durbin of Illinois, the Senate whip, said that all 55 members of the Senate Democratic caucus will vote for Hagel - though many Democrats have decided to publically withhold their support until after the hearing. Republican Senator Thad Cochran of Mississippi has said he will also vote for Hagel, which means Hagel need only muster another four GOP votes, assuming his nomination is even filibustered. Those four votes are riding on what Hagel, a former Republican Senator from Nebraska, says at his hearing. Senator John McCain, an Arizona Republican, and many of Hagel's erstwhile GOP colleagues, were upset when Hagel opposed the surge and became an outspoken critic of the Bush Administration on the handling of the Iraqi reconstruction. Hagel didn't help matters when he also endorsed Barack Obama over McCain in the 2008 presidential election and Democrat Bob Kerrey over Deb Fischer in last year's Nebraska Senate race. But, as Senator John Cornyn, a Texas Republican, said, "It's not a matter of personalities. Chuck Hagel's an honorable man. Republicans have other concerns such as Hagel's past comments advocating for direct engagement with Iran (a position once held by presidential candidate Barack Obama), past votes in 2001 and 2008 against Iran sanctions and a comment about how the "Jewish lobby intimidates a lot of people," for which Hagel has apologized. Republicans have also voiced concerns about Hagel's 2011 comments to the Financial Times that the Pentagon budget is "bloated." Others have also been upset at his support of a group called Global Zero, which seeks to eradicate nuclear arms globally, even though Hagel has said he would not support unilateral U.S. reductions. But as Hagel has made the rounds, meeting privately with GOP senators and Jewish groups, he has assuaged many concerns. Though they are withholding final judgment until after the hearing, McCain and Republican Senators Susan Collins of Maine, Nebraska's Fischer, Mike Lee of Utah and New Hampshire's Kelly Ayotte were much pacified after meeting with Hagel and their criticisms muted. "It was a pleasant conversation," McCain said, "between old friends." Thus far James Inhofe of Oklahoma, the top Republican on the Armed Services Committee, David Vitter (R-LA), Roger Wicker (R-MS), Tom Coburn (R-OK), Pat Roberts (R-KS), Dan Coats (R-IN) and John Cornyn (R-TX) have confirmed they will under no circumstances support Hagel's nomination. Senator Lindsey Graham, a South Carolina Republican, said he might move to block Hagel's nomination if Panetta does not agree to testify before the committee on the Benghazi attacks in September last year that killed U.S. Ambassador Chris Stevens and three other Americans. A Panetta testimony has not yet been confirmed. Democrats have voiced concerns about a comment Hagel made in 1998 about an ambassadorial nominee being "too gay" for the job, a comment for which Hagel has apologized. Democratic Senators Chuck Schumer of New York and California's Barbara Boxer, the strongest Democratic proponents of Israel, had voiced concerns about Hagel's stances on Iran. But both backed down after meetings with Hagel where he pledged to fully support Obama's policy of prevention. Hagel's financial disclosures this week also raised some alarm bells as he sits on the board of Chevron and Deutsche Bank, which is under investigation by the Treasury Department for its dealings with Iran. Hagel has said he'd quit those boards and divest his Chevron stock if confirmed. By Wednesday even Republicans aides were privately conceding that Hagel would be confirmed barring any major gaffes in Thursday's hearing. And attacking too overtly someone they will likely have to work closely with once confirmed might hold back some of Hagel's harshest critics. Which means that Thursday's hearing, while still pivotal, is more likely to clear Hagel's path than block it.