Three things you should know about Rob Nabors:

1. He loves lists, thinks in lists, breaks down plans of action into lists.

2. He prizes discretion and despises leaks, which is why Republicans say they can trust this Democrat. (And probably explains why he declined to comment for this piece.)

3. He may be the most important player you’ve never heard of in the ongoing “fiscal cliff” drama.

President Obama and House Speaker John A. Boehner (R-Ohio) made headlines on Sunday when they spoke directly about the fiscal cliff, but it’s Nabors, who is Obama’s chief congressional liaison, who’s in the closed-door negotiations that pave the way for such conversations — and deals.

The Washington Post’s Chris Cillizza looks at the potential dealmakers in the “fiscal cliff” talks. (The Washington Post)

“He’s our Congress whisperer,” says David Plouffe, a senior Obama adviser, of the famously soft-spoken Nabors. “Rob’s got a great instinct for where the deal lies, what Democrats are willing to do, what Republicans are willing to do. He’ll say, ‘Here’s what’s going on, here are what the odds are of success.’ He doesn’t ever paint a rosier picture than exists.”

The wonkish 41-year-old Nabors is also wading into the weeds of any potential fiscal cliff deal.

“It’s clear when you talk to Rob that he’s not someone just reporting the news at 1600 [Pennsylvania Avenue]; he’s helping to make the news at 1600,” says Mike Sommers, Boehner’s chief of staff.

“He is very methodical and takes you through things point by point,” says David Krone, Senate Majority Leader Harry M. Reid’s chief of staff. “And if it is a point that is a priority [for the president], he makes that clear.”

Nabors traveled to Capitol Hill with Treasury Secretary Timothy F. Geithner late last month to discuss the fiscal cliff with members of Congress. House Minority Whip Steny H. Hoyer (D-Md.) was one of those present. While Geithner was there as the president’s proxy, it was Nabors who was critical to explaining the president’s position. Hoyer recalls that “Geithner frankly said, ‘Rob is here for the details.’ ”

At which point Nabors started to tick off a list of key components.

Learning to fit in

Growing up, it wasn’t always easy being the son of a highly decorated Army major general who was moved from post to post to post. Nabors was the new kid in 15 different schools before entering college. His childhood spanned three foreign countries (Italy, Germany and South Korea) and six states that ran the gamut from blue to red (Massachusetts, Florida, Arizona, Maryland, New Jersey and Virginia).

Each time he moved to a new place, Nabors would pick up whatever sport ruled the day with the locals: football in the States, soccer in Europe. (He’s a Tottenham Hotspur fan.)

“Rob is a person of significant ability, and he’s always figured out how to fit in,” says Cassandra Butts, former deputy counsel to the Obama White House.

Nabors was finally able to settle in for four years in Notre Dame, Ind., where he began his college studies in 1989. Like many of his classmates, Nabors would become a fierce, lifelong fan of the school’s football team. His passion for the blue-and-gold would be an asset: Sommers displays a big Fighting Irish sign in his office; colleagues with competing loyalties know to expect e-mails from Nabors after big matchups.

As an undergraduate, Nabors focused on government and computer applications. His studies ultimately led him to enroll as a PhD student in the University of North Carolina’s political science program. He didn’t complete the program (he earned a master’s), but he came away with something else: an understanding of Robert Keohane, the highly influential international relations scholar, says Nabors’s former UNC adviser, Thomas Oatley. Keohane’s focus was on the global arena but would foreshadow what would lie ahead in Washington.

“Even among pure egoists, cooperation can ‘emerge’ if a large enough initial cluster of potential cooperators exists,” Keohane wrote in “After Hegemony: Cooperation and Discord in the World Political Economy,” his seminal book. “Ignorance of how to promote cooperation can lead to discord, conflict, and economic disaster before cooperation ever has a chance to prevail.”

Nabors would put Keohane’s theories to the test when he moved to Washington in 1996, where he first took a post as an examiner at President Bill Clinton’s White House Office of Management and Budget. His ability to handle complex projects and to help drive decision-making caught the attention of former OMB director Jack Lew (now Obama’s chief of staff), who quickly promoted him. Nabors next moved to the opposite end of Pennsylvania Avenue in 2001 and quickly rose to become the first African American staff director on the House Appropriations Committee, working for seven years for David Obey, who was the top Democrat on the panel and was as fiery as Nabors is level-headed.

“We used to joke that we were going to start a support group for guys like us who worked for guys like them,” says Democratic operative Sean Sweeney, a former staffer for Sen. Charles E. Schumer (D-N.Y.), another member not known for holding back.

Nabors never wavered from Obey’s directives, but he preferred to take a more diplomatic approach, simply walking over to Jim Dyer’s office to talk it out over sandwiches. “We did a little role playing: ‘If I could have this, you could have that,’ ” recalls Dyer, a former Republican staff director for the House Appropriations Committee. “In two years, I don’t think we had a cross word. He’s a man you can be candid with. It doesn’t blow up in your face.”

Dealing with Congress

Nabors was confirmed in 2009 as Obama’s deputy OMB director, working to hammer out the president’s stimulus plan in the earliest days of the administration. But out of the gate, the White House also leaned on him to deal directly with the many-headed hydra that is Congress.

Sweeney, who also worked as a senior White House staffer, recalls a 7:30 a.m. meeting when the news came that legislators were getting “really disgruntled” with one of the provisions of a major bill. “Rob’s bearing the brunt of it,” one staffer said, according to Sweeney. They all turned to look at Rob. “That’s okay; keep it coming,” he said, patting his chest with both hands. “That’s what I’m here for.”

In early 2011, when Republicans took over the House, Obama tapped Nabors to become his chief lobbyist on the Hill. The relationship between the White House and Republican lawmakers was acrimonious from the start, but Nabors was able to keep some channels of communications open, in part because of relationships he had forged. Steve Stombres — an old high school classmate of Nabors — is chief of staff to House Majority Leader Eric Cantor (R-Va.).

“He’s put in the position of having to be the guy representing our position [to the White House], and we knew that we could count on him,” Stombres told a Washington Post reporter in December 2011, adding that Nabors’s ability to be discreet was also key. “It’s the ability to have a discussion and not read about it in the press.”

Yet not all members of Congress — including Obama’s allies — have been thrilled with how the White House has handled high-stakes negotiations. The current fiscal cliff talks, for example, are being conducted almost exclusively in backroom meetings between Boehner’s office and White House advisers such as Nabors. “I speak for a number of members in the Senate who say, ‘Hey, we want to be involved in this discussion,’ ” says Sen. Bernard Sanders (I-Vt.).

There may be a reason why Nabors and the White House are playing it so close to the vest. On those rare occasions when Nabors loses his cool (“with a unique level of intensity,” says Sean Kennedy, a former staffer in the Obama White House) it usually involves an inopportune public disclosure. “It’s when there is a painfully orchestrated agreement in the West Wing on how we’re going to run a play, and then there’s a breach — either a leak in details of how we’re engaging the Hill, or when someone from outside the White House is suddenly negotiating with Congress,” Kennedy says.

Usually, though, it’s Nabors who tries to bring down the temperature in the West Wing.

“He sees his role as bringing us back to reality. ‘Okay, this is all interesting, but . . .’ ” says Gene Sperling, the president’s economic adviser. “He brings us down to earth.”

After Boehner walked away from the debt-ceiling talks with Obama in July 2011, morale was low in Obamaland, and it was Nabors who told the team, “Guys, we have to focus. What do we do now?” recalls Plouffe. “He quickly moves onto ‘What’s Plan B?’ ”

And if Nabors stays true to form during the fiscal cliff negotiations, he surely has a Plan C and Plan D, too.