Senator John McCain attends the Senate Foreign Relations Committee on Tuesday to argue the Obama administration's case for using military force in Syria on Capitol Hill September 3, 2013 in Washington, D.C.

WASHINGTON — It may not be on the ballot, but this midterm election will decide who leads one of Congress’ most important military committees.

If the polling holds, the Senate will be welcoming John McCain as the new Armed Services chairman come January, along with the experience and political fireworks he is likely to bring to the dais.

The powerful committee births U.S. military laws and defense budgets on Capitol Hill and is set for new leadership with the retirement of Sen. Carl Levin, D-Mich. The party that takes control of the chamber in the midterms will also hand the Armed Services gavel to their most senior member on the committee, either McCain or Rhode Island Democrat Jack Reed.

“The most likely outcome is a small Republican majority” in the Senate following the election, said Kyle Kondik, the managing editor for Sabato’s Crystal Ball, which tracks elections for the University of Virginia Center for Politics.

McCain, who has chaired the committee in the past, may be the most recognizable face on Capitol Hill following a run for the presidency in 2008.

On the Hill, McCain is known for digging into the details of military policy and being a fierce opponent of waste, which could take center stage for Armed Services if he runs the agenda. He has worked to reform military acquisition programs while lobbing criticisms of programs like the F-35 fighter jet and the Navy’s littoral combat ships.

McCain was among a group of senators who are fighting this year to save the A-10 Thunderbolt, popularly known as the Warthog, which is popular among infantry troops but is on the Air Force chopping block as the service scrapes to save money.

“He is one of those guys who digs down deep into the weeds on policy,” said Joshua Huder, a senior fellow at Georgetown University’s Government Affairs Institute.

His positions, along with his colleague Sen. Lindsey Graham, R-S.C., are often among the Senate’s most hawkish. He was among the first to call for airstrikes against the Islamic State in Iraq, and has been pushing the Obama administration to step up operations in Syria to unseat President Bashar al-Assad as part of the offensive.

McCain has been willing to reach across the aisle, which is a rare quality on the Hill these days. He partnered with Sen. Bernie Sanders, I-Vt., to pass a $16.3 billion overhaul of the troubled Department of Veterans Affairs.

Huder said McCain shares a lot of political views with outgoing armed services chairman Levin, who built a reputation as a thoughtful foreign policy thinker running a bipartisan committee. In a recent speaking engagement, Levin said he considered himself an “owl” on defense issues, as opposed to a hawk or a dove.

But their political styles differ dramatically.

While Levin is often measured in his public responses, the Arizona senator may be best known for his barbed political attacks and short temper with rivals. In October for example, he called the Pentagon’s top spokesman, Rear Adm. John Kirby, an “idiot” for his handling of Iraq war questions.

“Here’s the bottom line on McCain: He’s unpredictable,” said Gordon Adams, a professor of foreign policy at American University in Washington, D.C.

Despite a long track record on Capitol Hill, Adams said, it also remains unclear whether McCain is a “big picture” thinker capable of guiding military defense policy on the committee at a time of sweeping changes and surging danger.

The country is setting off on a new war in Middle East, facing a resurgent Cold War in Europe, struggling with massive defense budget cuts, and still slated for an historic shift of forces into the Pacific.

“We’re really at the point where the military has to rethink everything it is doing. We are at a defense reform moment,” Adams said.

Reed could still take the chairman seat if Democrats manage to hold onto the Senate on Election Day.

It seemed very unlikely in the days before the vote. The Crystal Ball analysis found it was “getting harder and harder to envision a plausible path for the Democrats to retain control of the Senate” and that the GOP were about to gain 5 to 8 seats.

Reed shares a history of military service — he graduated from West Point in 1971 with an active-duty commission in the Army — and a focus on the details of military policy with McCain. He is currently the chairman of the Armed Services Subcommittee on Sea Power.

One of his biggest accomplishments in military legislation was securing $17 billion this year for construction of Virginia-class submarines, which benefits the manufacturing base in Rhode Island.

Reed and his public style also contrast with McCain. He often sidesteps the media in the halls of Con-gress and where McCain can be gruff and impatient, Reed appears mild-mannered and soft-spoken.

As chairman, the Rhode Island senator would likely mirror Levin, who was an efficient manager and bipartisan broker who “kept the trains running” but not a major reformer of military strategy, Adams said.

“I’ve never had much of a sense that he’s a strategic thinker, but neither was Carl Levin,” he said.

tritten.travis@stripes.com

Twitter: @Travis_Tritten