Mabus doesn't enjoy Panetta's high profile in official Washington, but the Navy secretary has had a long and varied government career that could make him a good fit for the Pentagon's changing mission. Gates has been a wartime Pentagon chief who spent his first years in office helping to bring Iraq back from the brink of civil war. More recently, he's been a central player in the administration's decision to sharply escalate the Afghan war. His successor will face a fundamentally different set of challenges: overseeing the American withdrawals from Iraq and Afghanistan while reconfiguring the Defense Department to adjust to a new era of mounting budgetary pressures.
Gates hasn't announced when he plans to retire, but most military and Defense officials believe it'll be sometime this summer, probably in July. That would enable him to take part in the Obama administration's Afghan war review and help Obama decide how many of the surge troops to bring home. Adm. Mike Mullen, the chairman of the Joint Chiefs of Staff, is set to retire when his term ends October 1, so a Gates departure this summer sets the stage for his successor to play a major role in choosing Mullen's replacement as the nation's top military officer.
White House officials say they haven't begun interviewing possible Gates successors and have no timetable for doing so. Aides to Panetta say he hasn't been approached about the Pentagon job and, at 72, he expects his current post at the CIA to be his last government job.
Mabus is aware of the growing speculation he'll be tapped to replace Gates, but he declined to say whether he's been formally contacted for the position.
"I've got a wonderful job," he told National Journal during an interview in his Pentagon office. "I will stay in this job as long as the president wants me to."
Choosing his words carefully, Mabus added: "I read the same periodicals you do."
In the interview, Mabus said he was proud of his two years as Navy secretary, during which he's made broad cost-cutting and contracting reforms. There was the controversial decision to shelve a Marine expeditionary fighting vehicle. And he launched an ambitious effort to cut the Navy's use of oil in half by 2020 and replace it with renewable energy sources.
"For almost a decade, because of the two wars, everything got funded," he said. "Today, I think you have to make some hard choices. You have to think very critically about what the mission really is and what the nation really needs."
Cost-cutting skills will be a core part of the next Defense secretary's role, which plays to one of Mabus's strengths. The Pentagon's budget has effectively doubled in real terms since 2001, but the Obama administration wants the department's funding to increase by less than 1 percent in fiscal 2012 (the smallest such increase since the wars began), increase by even smaller amounts in fiscal 2013 and 2014, and then see no growth whatsoever in fiscal 2015 and 2016.
Mabus also enjoys close relationships with both Obama and the officer thought to be the front-runner to replace Mullen, Marine Gen. James Cartwright, the current vice chairman of the Joint Chiefs of Staff. Mabus, a former U.S. ambassador to Saudi Arabia, was one of Obama's senior Middle East advisers during the 2008 election cycle and campaigned extensively on his behalf. He was one of Obama's first picks for a high-level Pentagon job. After last year's BP oil spill, Obama tapped Mabus for a second powerful position: head of the administration's Gulf Coast restoration efforts.
"From day one, he was making speeches and crisscrossing the country for Barack Obama," said Marty Wiseman, the director of Mississippi State University's John C. Stennis Institute of Government. "The president would certainly have to view him as someone who's more than paid his political dues."
More recently, Mabus went to bat for Cartwright, a decorated officer who journalist Bob Woodward described in his book Obama's Wars, as the president's favorite general. Cartwright was accused of having an improper relationship with a young female officer. Pentagon investigators recommended he be disciplined for a pair of minor infractions, but Mabus overruled those recommendations and cleared Cartwright entirely.
If Mabus were chosen, it would cap a remarkable turnaround for a politician once seen as one of the Democratic Party's brightest young stars and later held up as a cautionary tale over the dangers of challenging entrenched local political systems.
Mabus, 62, attended the University of Mississippi and got a graduate degree in political science from Johns Hopkins University and a law degree from Harvard. He served two years in the Navy, finishing as a lieutenant.
Mabus clerked on the U.S. Fifth Circuit Court of Appeals and spent several years working as a lawyer for the House Agriculture Committee before returning to Mississippi. He won his first statewide race in 1983, when he was elected state auditor. Mississippi was then one of the most corrupt states in the country, and Mabus participated in a probe led by the FBI called "Operation Pretense." It eventually led to the arrests of 57 county supervisors from across the state. The probe, one of the biggest public integrity investigations in Mississippi history, catapulted Mabus into the governor's office in 1988.
"That's what made his name," Wiseman said. "He rode that wave straight into office."
Mabus was just 39 when he was elected governor, making him the youngest state chief executive in the country. A glowing 1988 New York Times Magazine cover story described Mabus as a "Sun Belt technocrat, the manager-politician." Mississippi had long been the nation's poorest, unhealthiest, and least well-educated state, but there were widespread hopes that Mabus would somehow be able to change all of that. In the Times article, a local resident said "Camelot has come to Mississippi." Mabus decided to focus on improving the state's abysmal education system, a fight that ultimately cost him the governorship. Mabus wanted to fund what he saw as much-needed school reforms by creating a statewide lottery, but that form of gambling was specifically banned by the state constitution. Lawmakers preferred to finance the changes by raising taxes. Mabus refused to budge. He lost the funding fight, dooming both his school reform plans and hopes for a second term.
Today, Mabus is in the running for one of the most high-profile and powerful posts in the country. His hopes of becoming the nation's next Defense chief now rest with a single voter, President Obama. For Mabus, a career politician turned senior Pentagon official, it all comes down to one final election.