In Kennedy’s towering shadow, Senator Kirk discreetly toils

It was typical of the low-key, insider’s posture Kirk has maintained since Governor Deval Patrick appointed him to temporarily fill the seat of the late Senator Edward M. Kennedy: discreet, in the background, studiously avoiding the spotlight.

Kirk has given few speeches, limited his press releases to a few nuts-and-bolts issues, and shunned almost all requests for interviews. He said he is honored to find himself a member of Washington’s exclusive club of 100, after working for decades in support roles as a Kennedy aide and top Democratic Party official. But he knows his role is temporary, and he is not seeking attention for himself.

“The old school would say that freshmen could be seen but shouldn’t be heard,’’ Kirk said in a brief interview. “My own sense is not to be pushy or in any way be disrespectful.

“While I have held other positions that have required leadership, my style isn’t to run for the lights and for center stage.’’

There may be limits to the caretaker role, however, even if he will be returning to Boston in January after Massachusetts voters pick a successor (Kirk is not among the candidates) to fill out Kennedy’s term.

Kirk acknowledged that he has been urged by some colleagues to take a higher profile. As a closely divided Senate pushes ahead on a sweeping health care overhaul, Kennedy’s signature cause, and on other issues such as the economy and climate change, some party colleagues want him to make himself heard, Kirk said.

His response has been to edge into more public discussions, while remaining on the cautious course. He gave his first floor speech last week, outlining his support for a government-run plan to compete with private insurance companies under the health care overhaul.

“Some of the folks who I have known probably would say: Because this is a short appointment, don’t let too many days go by before you contribute what we know you can contribute,’’ Kirk said. “I’m getting over this initial short-term freshman stuff, but you’re going to be a senior in a couple of weeks because you’re graduating in a hurry.’’

From the first moments he arrived in Washington on the day after his Sept. 24 appointment, Kirk has remained deferential to his former boss. Without alerting the press to what most politicians would view as an extraordinary photo op, he quietly stopped by Kennedy’s grave at Arlington National Cemetery and paid brief respects to his longtime mentor. From there, he went to Kennedy’s former office with its expansive view of the Capitol, to prepare for the move to his own more modest digs on the first floor.

In just more than a month in office, Kirk has voted 30 times, including on bills to amend Medicaid payments to doctors and approve a Defense Department spending plan. He also has been working on a variety of constituent issues that had accumulated since before Kennedy’s death on Aug. 25.

But American University history professor Allan Lichtman, who studies Congress, said Kirk’s highest-profile contribution will be to provide Democrats with “a pretty reliable’’ 60th vote to stymie potential Republican filibusters on health care and other legislation.

Colleagues say Kirk has fit in seamlessly, capitalizing on his friendly persona as well as his past as Kennedy’s top Senate aide in the 1960s and 1970s and as Democratic Party chairman during the 1980s. He received a standing ovation at his first caucus luncheon, has renewed old friendships among Republicans, and drawn support from senior Democrats, including Senators Dick Durbin of Illinois and Christopher Dodd of Connecticut, during his first floor speech last week.

Along with Dodd, an old friend, Senator John F. Kerry of Massachusetts has taken Kirk under his wing, and the two meet often. They co-wrote a letter to Senate majority leader Harry Reid on extending unemployment insurance, discussed strategy on the health care debate, and joined forces behind a bill that would help reduce greenhouse gas emissions and create clean energy jobs.

Kirk “has fit in, seamlessly and superbly,’’ Kerry said. “He’s been just extraordinarily well received by colleagues.’’

Though he has tough shoes to fill, Dodd said, Kirk is up to the challenge.

“We all miss Teddy. We all wish he were here,’’ said Dodd, who became close friends with Kirk as well as with Kennedy. “Paul, I know, wishes he was here. But in his absence, Paul Kirk is about as close to a great replacement as you can get.’’

Senator Ted Kaufman, a Delaware Democrat who is the interim replacement in Vice President Joe Biden’s old seat, said he and Kirk have much in common, including familiarity with the ways of the Senate and little ideological daylight between them and the senators they replaced.

That experience, he said, helped them “get accepted right away. You’re with a bunch of people - very smart, very knowledgeable people who have good senses of humor and are good to be around.’’

Kirk has been assigned to two important Senate committees: Homeland Security, which oversees domestic security issues, and Armed Services, which deals with military issues, including the Iraq and Afghanistan wars. The latter, he said, “is right in the headlights of a decision the president is going to have to make on Afghanistan. It’s going to be of enormous importance and impact. There are no easy answers.’’

At a Homeland Security committee meeting recently, he called for rapid delivery of the swine flu vaccine to protect college students traveling during the holidays. At a news conference, he joined Democrats’ push to extend unemployment benefits, calling it “a vital safety net’’ that as many as 40,000 Massachusetts residents could lose by year’s end.

Kirk insists he will use his influence more, though it is unlikely he would throw verbal bombs at Republicans or give fiery speeches. He said he simply intends to follow in Kennedy’s footsteps, using his quiet skills to help bring health care reform to the nation.

When he was appointed, “People said, ‘He’s the 60th vote.’ It could be the difference - as long as the other 59 are in place,’’ Kirk said. Still, casting a vote to overhaul the nation’s health care system - while seated at the vote of a legendary senator and dear friend - will bring emotions that are difficult to fathom.

If he gets to vote on a final bill, “that will be something, given my appointment to fill Senator Kennedy’s place,’’ he said, searching for words to describe his emotions.

“To cast it as a friend and interim appointee succeeding Senator Kennedy,’’ he said, pausing. “I don’t need to tell you the honor that would be.’’

And Kennedy himself would approve, Dodd said.