When President Barack Obama signed a $100 billion transportation bill in July, it was at once heralded by some for creating jobs, and criticized by others for what they called the creative funding formula related to pensions that helped pay for it.

In the center was Russell Sullivan, a veteran Capitol Hill staffer and chief of staff for the Democrats on the Senate Finance Committee.

Sullivan has been instrumental in helping to shepherd through some of the biggest tax legislation in the last decade, including the Affordable Care Act, the Obama administration’s health care law.

Sullivan says his 15 years working on Capitol Hill has made him more than just an expert in tax and pension issues. “You begin to understand the kinds of things members can do politically,” Sullivan said.

So when his boss, Senator Max Baucus (D-Mont.), needed him to come up with $20 billion for the transportation bill this year, Sullivan and his staff came up with several ideas for him to bounce off other senators. Of those, the most popular among the legislators seemed to be changing taxes, fees and requirements related to companies’ pension plans.

In a year when Congress repeatedly has been called dysfunctional, the bill passed, funding highway and transportation projects for two years. Some transportation interest groups criticized the bill for using the $20 billion in nontransportation sources.

The need to find that funding also came in part from Sullivan’s work on the congressional deficit commission, also known as the “supercommittee,” which was tapped to come up with a solution to the debt crisis. While the committee failed, some of the ideas stuck around, such as the notion that every appropriations bill needs to find a way to pay for any new spending.

The way he treats everyone with respect has drawn a following from both sides of the political spectrum, said Michaela Sims, a former Hill staffer and consultant with Bockorny Group. What’s more, his demeanor toward others has helped him through some tough negotiations. “He’s a master negotiator,” Sims said. “He sees the goal line and sees what he needs to get there.”

Sullivan is a top prospect to be hired away from the Hill because of his knowledge of tax issues, lobbying shops told Roll Call in July.

Looming economic issues will again put a spotlight on Sullivan, who previously worked for former Florida Senator Bob Graham (D) and as chief tax counsel for former Senator Daniel Patrick Moynihan (D-N.Y.) before starting with Baucus in 2001. Tax cuts are set to expire, and Congress has agreed to impose mandatory spending cuts, a combination now called the “fiscal cliff.”

The resolution of this cliffhanger will likely be coming out of the Senate Finance Committee — with Sullivan’s guidance. — Todd Ruger