In their Democratic primary for the U.S. Senate, Rep. Ed Case, 53, calls for "a new generation of leadership," while 81-year-old incumbent Sen. Daniel Akaka talks about the virtues of a kupuna's wisdom.

We've danced around the sensitive subject of age without really confronting the question head-on: Is a candidate's age a fair issue for voters to consider?

It is in a U.S. Senate race — especially when the octogenarian candidate is the "junior" member of the state's delegation.

Hawai'i is a small state heavily dependent on federal spending — so much so that Hawai'i's senior Sen. Daniel Inouye, also 81, has been called the second most important leg of the local economy behind tourism for his success in bringing home federal funds.

Inouye and Akaka always say that seniority is everything in the Senate, and Inouye is so successful at funding Hawai'i projects in good part because he ranks third in Senate seniority at 43 years.

But Akaka isn't nearly in Inouye's league, with only 16 years of seniority. It's doubtful he could deliver the same clout as Hawai'i's go-to guy in Washington if Inouye were to leave the Senate first.

The question isn't whether it's a problem to have a senator who is in his 80s; many political leaders have served with distinction at that age and beyond.

The potential dilemma for Hawai'i is having two senators in their 80s who could both depart office around the same time, leaving us handicapped with two tyro senators who have virtually no seniority.

That's why it's fair for voters to consider whether it would make sense to have a younger junior senator learning the job and gaining seniority while Inouye is still around to do the heavy lifting.

This is the case with the two senators who have more seniority than Inouye, Robert Byrd of West Virginia and Ted Kennedy of Massachusetts.

Both have somewhat younger men prominent in their own rights building up seniority behind them — Jay Rockefeller in West Virginia and John Kerry in Massachusetts.

No matter how good a job somebody does, the work is never finished until the way is paved for a worthy successor.

It's worrisome that Akaka and Inouye, who has already announced he'll run for re-election in 2010 at 85, show little concern for the importance to their constituents of a smooth succession.

There was a time when Hawai'i Democrats touted the value of having young and ambitious representation in Washington.

Inouye has all that seniority because he was first elected to the Senate at 37. Hawai'i's other Washington icons, Patsy Mink and Spark Matsunaga, went to Congress at 37 and 46, respectively.

Now, Inouye and Akaka protect their turf by essentially claiming to be irreplaceable because of their age and experience, a conceit that bodes ill for Hawai'i's future inasmuch as both will have to be replaced in the not-too-distant future.

When pressed on succession, Akaka suggests Rep. Neil Abercrombie as his eventual replacement.

With all due respect to Abercrombie, he's 68 now and would be 74 the next time Akaka's seat opens.

Would it serve Hawai'i's interests to replace an octogenarian senator with a septuagenarian who could run out of productive years before he earned enough seniority to be able to go to the bathroom without raising his hand?

Electing a U.S. senator is one of the most important decisions we make, and age certainly isn't the only issue in this election — or necessarily the most important.

But given our dependence on the federal government and the importance of assuring Hawai'i's long-term influence in the Senate, it would be a mistake to exclude age from candid discussion.

David Shapiro, a veteran Hawai'i journalist, can be reached by e-mail at dave@volcanicash.net. Read his daily blog at blogs.honoluluadvertiser.com.