(Reuters) – He joined the Senate knowing more about it than many of its members. He gave himself a two-year term limit, went to work and won bipartisan praise.

Barack Obama

Since replacing his former boss, Vice President Joe Biden, in the Senate in January 2009, Democrat Ted Kaufman has been a most unusual lawmaker.

With no desire to mount a campaign or keep political power, Biden’s longtime former Senate chief of staff hasn’t had to spend time raising millions of dollars to run for office. Instead he’s been free to focus on the nation’s needs and those of his home state of Delaware.

He’s taken on Wall Street and healthcare fraud. He’s helped shape U.S. policy toward Iran. He’s pushed to protect the environment. He’s visited war-torn Iraq and Afghanistan. He’s gone to the White House to witness President Barack Obama sign into law major legislation that he helped craft.

“I’m trying like hell to make a difference,” said Kaufman, 71, seated in his Senate office. “This is a great place. It’s really, really interesting, challenging.”

“I wouldn’t say what I’m doing is fun. But like when I was Joe Biden’s chief of staff (for 19 years), when I go home at night, I don’t have to wonder what I’m doing with my life,” said Kaufman, who is tall and angular with thinning curly hair.

Kaufman was appointed to the Senate by then-Delaware Governor Ruth Ann Minner after he helped Biden and Obama win the White House in the November 2008 election.

Before taking office, he said he would leave it after two years. He said he had no interest in running for a full six-year term this year, saying that would be a distraction.

“If you run for the Senate — particularly someone like me who was appointed to it — you’re going to spend 65 percent to 70 percent of your time organizing your campaign and raising money,” Kaufman said. “And if you lose, you will never really have experienced being a senator.”

While freshmen lawmakers are traditionally seen but not heard, Kaufman has been heard and seen, and has had an impact.

“He’s been as savvy and productive as anybody I have ever seen or even heard about in their first two years in the U.S. Senate,” said Norm Ornstein, a congressional scholar at American Enterprise Institute, a Washington think tank.

Senator Jeff Sessions, a conservative Republican, smiled when asked about Kaufman, a liberal Democrat.

“He’s a good man and he has a deeper understanding of the Senate than probably 70 percent of the senators here,” said Sessions.

CROSSING THE POLITICAL AISLE

While Congress has been torn by partisan fighting, Sessions said Kaufman “has been willing to cross the political aisle.”

Just weeks after being sworn in as a member of the Senate, Kaufman joined Senate Judiciary Committee Chairman Patrick Leahy, and Charles Grassley, senior Republican on the Senate Finance Committee, in introducing the Fraud Enforcement and Recovery Act to bolster tools and resources for federal investigators to combat financial fraud.

The measure passed the Senate 92-4.

With Kaufman at his side, Obama signed the measure into law on May 20, 2009. Kaufman was back at the White House last month when Obama signed a landmark overhaul of U.S. healthcare.

Working with fellow Senate Democrats Leahy, Arlen Specter and Herb Kohl, Kaufman crafted the anti-fraud provisions in the healthcare measure.

“I just had a small piece of the healthcare bill, but it was an important part. Everybody had a part of it. It really was a (Democratic) team effort,” Kaufman said.

Kaufman entered politics from private business. He was working at DuPont, the chemical company that is a major presence in Delaware, in 1973 when he became a volunteer with Biden’s first campaign for the Senate.

In 1976 he became Biden’s chief of staff, a job he held until 1995 when he became co-chair of Duke Law School’s Center for the Study of Congress.

That year Kaufman also became a member of the Broadcasting Board of Governors, a federal entity responsible for government sponsored, nonmilitary international broadcasting.

He held that post until 2008, when he served as a senior adviser on Biden’s campaign and later as a top aide on the vice-president-elect’s transition team.

During the hunt for a Senate replacement for Biden, who served in the chamber for 34 years, Biden’s son, Hunter, asked Kaufman, “Why not you?”

Kaufman thought of a number of reasons, including that he was then 70 years old and looking forward to a more placid life away from the rough-and-tumble of Washington.

“I never thought of being a senator. I never dreamed of it,” said Kaufman, who saw himself as a member of the political supporting cast, not a headliner. But after further reflection, and with encouragement from his family, Kaufman took it.

Kaufman rejects suggestions he was appointed as “a seat warmer” until Biden’s son, Delaware Attorney General Beau Biden, won it in the 2010 election.

When Beau Biden made a surprise announcement in January that he wasn’t going to run for the Senate, pressure mounted on Kaufman to reconsider and seek the seat.

Kaufman declined. “I will continue to spend my time as senator serving the people … not running for office,” he said.