U.S. Sen. Daniel Akaka agreed yesterday to appear in a single televised debate with U.S. Rep. Ed Case, giving voters statewide the chance to watch the candidates one-on-one before the Democratic primary for Senate in September.

AARP Hawai'i will sponsor the debate that will be aired live on PBS Hawai'i on Aug. 31.

Some within Akaka's camp had been resisting a debate, and Case had made it a campaign issue, accusing the senator of hiding behind his advisers.

"Accepting the AARP event, which will be broadcast on public television, meets the public's desire for this kind of forum and does not give an unfair advantage to any single commercial entity," Andy Winer, Akaka's campaign manager, said in a statement.

Akaka declined debate invitations from The Advertiser and KHNL-News8, KGMB9, KITV4 and KHON2.

Case, at a news conference at his campaign headquarters, thanked AARP Hawai'i and PBS Hawai'i for the opportunity. But the congressman said public television does not have the viewership of the commercial stations and noted that thousands of people may have already voted by absentee ballot by the time the debate airs.

"I suppose I should be grateful to Senator Akaka for agreeing to one debate during this campaign," he said. "Obviously, though, the Akaka campaign's motivation is to avoid as many debates as possible and to minimalize these debates."

The Akaka campaign said the senator's acceptance of AARP Hawai'i's invitation is subject to negotiation on the debate's format. The senator, for example, will not agree to candidate-to-candidate questions.

Case said Akaka's advisers are trying to micromanage the format and, if he is not allowed to ask Akaka questions, he would mention his disappointment during the debate.

"That's what happens on the floor of the United States Senate," Case said. "On the floor of the United States Senate, people stand up and debate. And debate is about questioning each other. A debate is about answering questions and defending one's position and advocating and probing for weaknesses in the other position."

Some of the issues that separate Akaka and Case include the war in Iraq, the USA Patriot Act, oil drilling in the Arctic National Wildlife Refuge, the Bush administration's tax breaks and the Jones Act.

Gerald Kato, chairman of the University of Hawai'i-Manoa's School of Communications, said debate analysis by political observers and the news media often emphasizes style over substance. But debates also give voters the chance to compare how the candidates respond to questions without the filter of the media.

"I'm a great believer in having the opportunity to hear what the candidates have to say about the issues," Kato said.

Debates can pose a risk for incumbents because they can legitimize challengers as equals in front of voters. Debates also can be unpredictable and can trigger mistakes that undermine themes the campaigns have spent months cultivating.

Akaka, 81, will be under added pressure because viewers will be judging whether he is still capable of doing the job. The senator handled himself with poise when he delivered speeches at the state Democratic convention in May and at a Hawai'i Publishers Association luncheon last week, the two previous times he has appeared before the same audience as Case. But the senator looked uncomfortable at times when answering questions from the audience at the luncheon.

Case, 53, will have his own challenges. He has to show that he is Senate material, but may alienate voters if he comes across as too glib or is seen as hectoring the likable Akaka.

"When elections are going to be as close as I think this one is going to be, it can hurt," Dan Boylan, a history professor at UH-West O'ahu, said of a poor debate performance.

"But I'm not sure that there's a lot of risk, if there's only one (debate). If you go two or three and it wears down and really does become a debating contest, remember one guy's a lawyer (Case) and one's a schoolteacher (Akaka).

"I think you can always bet on the lawyer to at least command the ground. Whether he commands the ground on the issues for the voter, that's another thing."

Barbara Kim Stanton, the state director for AARP Hawai'i, said the group will discuss the format, including how the debate will be moderated and how the questions will be chosen and asked, with the campaigns.

"AARP is really interested in making sure that the issues are heard," she said. "This is an important election."

Karen Yamamoto, interim president of PBS Hawai'i, expects the debate to draw an audience beyond the station's 20,000 members and its regular viewers.

"I think that because we have the exclusive broadcast, everyone will be watching," she said.

Reach Derrick DePledge at ddepledge@honoluluadvertiser.com.