Spurred by the knowledge that their two Senators will celebrate their 80th birthdays next month, Democratic legislative leaders in the Aloha State — in a circumstance that mirrors an ongoing debate in Massachusetts — are considering introducing a measure to take the power of filling a Senate vacancy away from Republican Gov. Linda Lingle.

Working with their first Republican chief executive in 42 years, Democrats, who control both houses of the state Legislature, are keenly aware that if tragedy befell either Sens. Daniel Inouye (D) or Daniel Akaka (D), Lingle has the power to name a replacement.

“It makes it more difficult for us with a Republican governor if one moves on,” state Senate President Robert Bunda said. “Democrats would have to aggressively look at the interpretation of the law.

“We haven’t been as aggressive in looking at this,” Bunda said, noting that Democrats are considering looking more closely at the issue now.

Faced with prospect of Republican Gov. Mitt Romney being given the power to appoint a new Senator if Sen. John Kerry (D-Mass.) is elected president in November, Massachusetts’ Democratic-controlled Legislature on Friday stripped Romney of his appointment authority and created an immediate special election instead.

Despite their advanced ages, Inouye is running for re-election this year, and Akaka is expected to run for a third full term in 2006.

While both are in relatively good health, Democrats know that if something happened to one of them, Lingle would no doubt appoint a Republican who then would become the natural frontrunner for a full term when the departed Senator’s term expires.

Current Hawaii law allows a gubernatorially appointed Senator to serve until the next election.

Akaka served seven months of the late Democratic Sen. Spark Matsunaga’s term before he had to stand for election in November 1990.

Juggie Heen, executive director of the Hawaii Democratic Party, said he would be “very surprised” if Inouye declined to finish his eighth term in 2010, when he would be 88. He faces only token opposition in his re-election campaign. Heen said Akaka also assured him that he would seek and complete a third term.

Bunda also assumes both men intend to stay in the Senate.

“I don’t think either will step down anytime soon,” Bunda said.

As to their health, Bunda said the men are very energetic and doing well.

Heen joked: “They both have the benefit of Asian longevity.”

Nonetheless, ambitious politicians naturally eye the opportunity to move up and political watchers assume several people would jump into any open or special Senate election.

“Nobody can really replace Senators Inouye or Akaka but there are people who have put in long service in Hawaii who would probably run,” said Richard Port, a Democratic National Committeeman from the Aloha State. “No doubt we would find good people to replace great ones.”

Inouye, a World War II hero who has served in elected office since before Hawaii achieved statehood, is beloved by Hawaiians and is a legend on the archipelago.

Democrats need look no further than their two Representatives for would-be candidates, Heen said.

The public likely perceives Rep. Neil Abercrombie, who has served 14 years in the House, as the “heir apparent” to either Senate seat, Heen said.

After waiting in the wings for so long, with no opening in immediate sight, Abercrombie is “conservatively antsy” to get a crack at the Senate, Heen said.

“Neil would certainly seem to be a logical person to step in,” Port opined.

But Heen cautioned anyone from thinking that Abercrombie would have a clear path to the Democratic nomination.

Rep. Ed Case, who won two special elections to succeed the late Rep. Patsy Mink (D), one in 2002 to finish her term and another in January 2003 to serve the spot she posthumously won in the 108th Congress, would also likely be interested, Heen said.

“He’s not noted for observing tradition,” Heen said of Case, confirming that Case is not likely defer to Abercrombie. Case does not have a “wait your turn” mentality, Heen added.

Another oft-mentioned name is that of Matt Matsunaga, son of the late Senator. Matt Matsunaga lost the 2003 special House election to Case.

Heen was reluctant to offer names but said the party “absolutely” has the timber to keep all four Congressional seats should a Senate seat become available and set off a chain reaction through the delegation.

Buoyed by Lingle’s 2002 win, Republicans are optimistic about their chances to win an open Senate seat or even to capture a House seat in November.

While the party’s current focus is on evening out Democrats’ lopsided majorities in the state Legislature, the state GOP chairman said he is “very confident about anyone’s chances” of winning an open Senate seat.

“We have a good chance to win a seat in Congress this year,” Brennon Morioka said.

He would not speculate about would-be GOP Senate candidates but rather talked up the two Republicans trying to unseat Abercrombie and Case.

For their part, Democrats are convinced Lingle would either run or, if the vacancy occurred mid-term, possibly try to appoint herself to the Senate. “The Republicans would be very aggressive in trying to win that seat,” Bunda said. “The governor would probably run.”

Showing how vehemently Democrats dislike Lingle, Port would only say “heaven forbid that she should represent Hawaii in Washington.”

Morioka denied that Lingle would jump at the first available Senate seat.

“She’s never talked about it,” he said.

Lingle will finish her first term as governor and seek a second in 2006 and “won’t focus on anything else,” Morioka said.

As for any possible Democratic effort to rewrite the state’s Senate succession law, Morioka said Democrats would be unwise to try.

“It would take a constitutional amendment,” he said. “It would be a difficult sell. Why now?” he asked, noting that the public would view any such effort as highly political.

“It would come off as extremely partisan and petty,” he said.