But on this occasion, nothing captures Dan Inouye's attention quite like the tiny scrap of yellowed paper set off to the side and easily missed.

"This I'm proudest about, above all else," he says, pointing out the "junior police officer" certificate he received in elementary school.

His animated smile betrays the statement, showing that the third-most senior member of the U.S. Senate doesn't lack a sense of humor.

It might not always be on public display, but it's part of the style that has led to Inouye's immense popularity and helped the seven-term Democrat become arguably the most powerful politician Hawai'i has ever seen. Inouye won his seventh term in 1998 with 76 percent of the vote.

As he celebrates his 80th birthday today, the decorated World War II veteran known to constituents simply as "Dan" says there's still work to be done as he continues his mission of trying to improve the quality of life in his beloved Hawai'i.

That means not even taking time off to celebrate his milestone birthday.

"I'll go to my office because we resume our session on that day — it's a Tuesday," he says.

Inouye's work has kept him busy since he was elected as the first U.S. House member from the new state of Hawai'i in 1959. He was elected to a full term in 1960 before winning his Senate seat in 1962.

His service in World War II was with the Army's storied "Go For Broke" 442nd Regimental Combat Team made up almost entirely of Japanese-Americans. The experience cost him his right arm, which was shredded by a German rifle grenade as he led an attack in Italy that killed 25 Germans and captured eight others.

It also earned him the Medal of Honor, the government's highest award for valor, further cementing his popularity among Hawai'i residents who first voted him into the Territorial Legislature in 1954.

Today, as he campaigns for his eighth term in the U.S. Senate, Inouye's schedule is as busy as ever, with appearances and speeches almost every day.

"I don't know whether I should tell you this, because you might think I need some psychiatric examination," he says as the wry smile returns to his face, "but I've never had a vacation in my life."

There's still work to be done, Inouye said, and he is far from content with what he's done so far.

"I can't think of anyone saying, 'I've done everything I wanted to do and I've finished it,' " Inouye says. "But in most cases, from the standpoint of my legislative work, I'm very happy with what we're doing now, and there's certain things I'd like to continue."

Specifically, he speaks of continuing his work on the Senate Defense Appropriations Committee that in recent years has secured the state hundreds of millions of federal dollars for military improvement, renovation and expansion projects.

The Air Force broke ground last month on a $190 million project to house a squadron of eight of the military's newest C-17 cargo aircraft. Construction is expected to start next month on the first of 28 projects for the Army's Stryker brigade being based in the islands.

He's proudest of the work he's done for Native Hawaiians, whether it's lobbying support for the Akaka bill or securing federal funds for a scholarship.

The work is a promise kept to his mother, Kame, who died 13 years ago.

Orphaned at age 4 — her mother died at childbirth and her father died working on a plantation near Lahaina — young Kame was taken in by a Native Hawaiian couple.

"She always looked back (at it) as the happiest moments in her life, and she always made me promise that I would do whatever possible to show her gratitude to them. She says, 'I can't do it, but you can do it.' "

Ask him if he ever reflects on his importance to Hawai'i, and Inouye deflects the praise.

"If you're trying to suggest that I'm indispensable — no," he says. "There'll always be someone."

Someone else, sure, but probably not one who's been able to work within the political system the way Inouye has, says Dan Boylan, a political analyst and history professor at the University of Hawai'i.

"He's meant extraordinary leverage in Congress," Boylan says. "He's been an insider, he's played the insider game and he's played it as well as anybody.

"He recognized long ago that a small state like Hawai'i has got to work both sides of the aisle. He's done it and he's done it masterfully."

And he's not ready to give it up just yet, either.

"I'm being as candid as I can be," Inouye says when asked how much longer he plans to seek office. "I've crossed the bridge and I've already burned it.

"I had an opportunity in the mid-70s to change the course of my life. I was given many opportunities to enter into law practice — invitations of fantastic amounts. But, to no surprise to anyone, I turned them all down because I enjoy this work, and I really mean that.

"Now, some have said, 'Aren't you regretful that you were wounded, therefore you were not able to follow your first dream of becoming a surgeon?' Oh, there are times when I look back and ponder as to what life would've been like if I were a surgeon, but I can't find any fault with this life."

And before it's all over, he hopes to add the one title that has eluded him throughout his distinguished career, although it's one that won't be his call. That will be up to his son, who just got married in May.