Who should fill Kennedy’s seat?

On Tuesday, the state’s senior senator sent a letter to the legislative leadership and Governor Deval Patrick, asking that they revise the current law to allow for an interim Senate appointment during the special election to fill a vacant seat.

“As I look ahead, I am convinced that enabling the governor to fill a Senate vacancy through an interim appointment followed by a special election would best serve the people of our Commonwealth and country should a vacancy occur,’’ Kennedy wrote.

Gerry Doherty, Kennedy’s longtime friend, says the senator is particularly concerned that the state be fully represented during the upcoming debate about expanding health care, a cause close to Kennedy’s heart.

“He is very sensitive to its importance, and he also knows that every vote counts,’’ says Doherty.

That reality will no doubt engender hostility from those against sweeping health care legislation. Still, given that this state has repeatedly reelected Kennedy, one of the Senate’s longest and strongest proponents of expanded health care, that hardly seems like a legitimate reason for opposition.

On Beacon Hill, the response has been muted, to say the least. Senate President Therese Murray and House Speaker Robert DeLeo issued a joint statement that, though complimentary to Kennedy, was noncommittal about his proposal. Of course, the senator’s letter comes against the backdrop of strained relations and mistrust over motives between the legislative leadership and the governor - an atmosphere that could complicate matters considerably.

Republicans, meanwhile, are already objecting. House minority leader Brad Jones declared yesterday that he was “shocked and appalled by the blatant hypocrisy,’’ noting that in 2004, Democrats rewrote the law to prevent Mitt Romney from appointing a Republican to fill John Kerry’s seat in the event Kerry won the presidency. Under the old law, an appointed replacement for Kerry would have served almost two years in the Senate; under Kennedy’s plan, the interim senator would serve four or five months.

The 2004 revision made a special election the way to fill a vacant seat, a change Kennedy advocated. At the time, lawmakers rejected a GOP amendment to allow the governor to make an interim appointment during that election. It’s unclear whether Kennedy had a position on that issue.

So it’s true that doing as Kennedy wants would mark a decided about-face for Beacon Hill Democrats. But the fact of the matter is that their 2004 move was simple, unadulterated power politics, and not a careful decision about what’s best for the state. Thus it’s hardly a compelling reason not to change the law now - not, that is, if a way can be found to keep the process fair. There, Kennedy’s suggestion is a good one: An interim appointee should have to make an explicit commitment not to run in the special election to fill the seat.

Who might such an appointee be? Vicki Kennedy is one oft-mentioned name. Confidants of Mrs. Kennedy have said she has no interest in serving either as an interim senator or as a candidate to replace her husband. No doubt it’s hard to consider any of that with her husband battling brain cancer. Still, she would be a fine choice as an interim figure.

That said, Mrs. Kennedy, who is smart and well-liked in political circles, and who has been not just Kennedy’s wife but his political partner as well, would also be an attractive candidate to succeed her husband on a longer-term basis. The view here is that she shouldn’t prematurely foreclose that possibility.

Another obvious name is former governor Michael Dukakis. At 75, he has put his political ambitions behind him. But he cares passionately about health care, having made expanded coverage a top cause both as governor and as the 1988 Democratic presidential nominee.

With his dramatic letter, Kennedy has opened the door for a discussion that would otherwise have been difficult to have out of respect for the senator’s sensibilities: What’s truly best for the state when a Senate seat becomes vacant? Beacon Hill leaders needs to debate that issue, not duck it.

Scot Lehigh can be reached at lehigh@globe.com.