Sen. Tim Kaine (D-Va.) talks to reporters before heading into a members-only classified briefing about Syria at the U.S. Capitol on Tuesday. (Chip Somodevilla/Getty Images)

Timothy M. Kaine arrived in the Senate in January ready to focus quietly on domestic policy and forge partnerships with Republicans.

The “quietly” part hasn’t quite worked out — but working with the GOP certainly has. This month, Kaine (D) finds himself at the center of Congress’s debate over whether to allow President Obama to launch military action against Syria. He is in charge of the subcommittee that handles Middle East policy. And he is standing with a Republican to strengthen the requirement that presidents seek permission before taking the country to war.

The result has been heavy exposure for the junior senator from Virginia — and a new role for a former Democratic Party chairman whose top job description was defender-in-chief of the president.

Although Kaine has been thrown into subject matter he didn’t seek out, it may be exactly the role he was looking for.

A former missionary to Honduras, Kaine 55, has been preoccupied with the “divided political leadership class” for much of his career. Working his way up from Richmond city councilman to mayor, lieutenant governor and then governor, Kaine consistently cast himself as a bridge-builder before serving in the decidedly partisan role of party chairman.

As of Sept. 4, lawmakers appear to be tentatively dividing into four camps over military action in Syria.

Forging ties across the aisle is a huge challenge in the modern Senate, which is stocked with partisan lawmakers less interested in compromise than many of their predecessors. Kaine's approach is badly needed, his friends say, and could establish him as a leader in transforming an institution that by many accounts is broken.

“Tim is relentlessly optimistic,” said Mark R. Warner (D), Virginia’s other U.S. senator. “It may seem crazy at times, but that’s what this place needs — more of that relentless optimism.”

Kaine’s pairing with Sen. John McCain (R-Ariz.) to revise the War Powers Act has attracted international attention as Obama makes the case for intervention in Syria. Kaine called it a victory when the president sought congressional authority for the strike; at a Senate Foreign Relations Committee hearing last week, he said he now supports granting that authority.

“The Constitution reserves the power to initiate military action to Congress,” Kaine said at the hearing. “Five-hundred-and-
thirty-five people get to vote on that.

Venn diagram theory

Working with McCain is just one in a string of partnerships with Republicans that Kaine has formed during his first eight months in the Senate.

He has worked with Sen. John Thune (R-S.D.) on overhauling the budget, and Sen. Deb Fischer (R-Neb.) on an amendment calling for an end to the sequester.

During an interview before the Senate broke for August recess, Kaine noted that he had spent that morning meeting with Sen. Ronald H. Johnson (R-Wis.) in Johnson’s office on budget issues and the previous night having dinner with tea party hero Sen. Ted Cruz (R-Tex.). Through a spokesman, Cruz said that Kaine brings a “seriousness and a civility” to the Senate.

“We get along well because we are both big readers and legal nerds,” Kaine said of Cruz. “We talk about books we’re reading, and we talk about what motivates us.”

Then there’s Sen. Mike Lee (R-Utah), another darling of the tea party.

Kaine is a longtime friend and political ally of Obama, while Lee has previously threatened to block every one of the president’s nominees. Kaine helped sell Obama’s health-care bill, while Lee has made it his mission to defund the law.

Not surprisingly, they rarely vote together — which is exactly why Kaine vowed to find a way for them to team up.

“The first time I saw one of those [vote] rankings . . . I went to Mike Lee and said, ‘Hey Mike, I saw something. You and I don’t vote together very much,’ ” Kaine recalled. “And he laughed, and I said, ‘I bet we’re going to find something we can work on.’ ”

Eventually they did: The space program is important to both Utah and Virginia, so they worked together to request a Pentagon report on the solid rocket motor industry.

Kaine has also offered the Troop Talent Act with Sen. Saxby Chambliss (R-Ga.), and a battlefield preservation bill with Sen. Thad Cochran (R-Miss.).

Fischer and Kaine have become especially friendly, first bonding during freshman orientation and then traveling together to the Middle East. The two senators — de facto social chairs for their class — also worked together to arrange an evening tour of the Library of Congress for their fellow freshmen. Fischer is trying to plan another bipartisan outing.

That bond helped Kaine and Fischer work together at a recent Armed Services markup on language calling for an end to sequestration. The two senators crafted the language on the fly, then edited it at the hearing room table. Their colleagues on the panel quickly agreed to adopt it.

“If you can develop relationships with people and have a chance to get to know them, it’s just helpful,” Fischer said. “There’s not too many issues that Sen. Kaine and I will probably agree on, but we will continue to find things on which we agree.”

Kaine explained that he seeks out a Republican sponsor for every bill “a) because it’s more likely to pass if I do, and b) I do think we have to show the American people we can work together. That’s the weakness of the Capitol right now, that’s the weakness of Congress. They don’t feel like we can work together.

“It’s the Venn diagram theory of politics,” Kaine said, which he learned as governor while working with the Republican state House speaker, William J. Howell (Stafford).

“We disagreed 80 percent of the time,” Kaine said. “But we were friends and we talked, and then we could find the 20 percent in that Venn diagram where you had the overlap. Differences are obvious. Similarities take more time to discover.”

Accidental spotlight

The focus on Syria and foreign policy wasn’t one Kaine had sought out. He campaigned last year mostly on domestic issues — particularly education — and he asked for a seat on the Health, Education and Pensions Committee as well as Armed Services, a natural for Virginia.

He didn’t get the HELP seat, instead landing on Budget and Foreign Relations. And almost by accident, he was handed the gavel of the subcommittee that oversees policy in the Middle East, a region whose divisions make the Senate look harmonious. The post opened because the previous chairman left the Foreign Relations Committee in July; Kaine’s first choice was the subcommittee that handles Latin America, but that wasn’t available.

The move gave Kaine a major voice on the Middle East, with ongoing conflicts in Syria and Egypt, the perpetually stalled Israel-Palestine peace process, and the Iranian nuclear program all falling under his purview.

He found himself talking about Syria on Face the Nation on Sunday and MSNBC’s “Morning Joe” on Tuesday before tackling the issue during two days of hearings, a Thursday meeting with ROTC cadets at Virginia State University in Petersburg, and a Friday roundtable with veterans on the War Powers Act.

“It happened real fast, and it was definitely a surprise,” Kaine said of the committee post.

Democratic leaders haven’t given Kaine any formal role or title, but as a former DNC chairman elected repeatedly in a swing state, he is regularly mentioned as a possible candidate to head the Democratic Senatorial Campaign Committee some day.

At the moment, he sounds more interested in focusing on his new friends across the aisle.

“I do feel like I’ve still got a steep learning curve to climb to be a good senator, and I want to make sure that I climb that curve before I take on any other kind of responsibility,” Kaine said.

“And I also have a little bit of feeling like, ‘Hey, I gave a year and a half of my life full time, plus a year of my life when I was governor and on weekends.’ I gave time to that cause.”