U.S. Rep. Mazie Hirono and former congressman Ed Case are familiar figures in Hawaii politics, but in their Democratic primary for U.S. Senate they will ask voters to judge them not only by their pasts, but by their potential to lead Hawaii’s congressional delegation for the next few decades.

Democrats will decide next August whether it is Hirono or Case who should carry the standard to replace U.S. Sen. Daniel Akaka, 86, who is not seeking another six-year term. But a longer shadow cast over the campaign is the likelihood the new senator will inherit the most influential mantle in the delegation when U.S. Sen. Daniel Inouye, 86, departs.

Hawaii has relied on the federal money and the leverage that Inouye, the chairman of the Senate Appropriations Committee and the Senate president pro tempore, has provided from Washington, D.C. Democrats have to measure whether Hirono or Case is capable of eventually performing a similar leadership role.

"What I know they want is a senator who is going to protect Medicare and Social Security, who shares their values," said Hirono, 63, who represents rural Oahu and the neighbor islands in the 2nd Congressional District.

"And they know that I share those kind of values. And not only do I share those values, but I share many of their experiences. I was raised by a single mother who worked really hard to put food on the table, who knows what the struggle is — economic struggles. I went to public schools.

"My mother is 87 years old and so I know how important Social Security and Medicare is to her, and to all the seniors in our state. So it’s shared values, shared experiences."

Along with protecting Social Security and Medicare, Hirono said, she would base her campaign on themes such as job creation, early childhood education and improving public schools to close the achievement gap linked to race and poverty.

While Hirono sees value in a bipartisan approach to certain issues, she fully embraces the Democratic label and is among the most liberal in the House. "The people want somebody who is going to stand up for those values and not just stand around in the middle of the road trying to figure out where to go," she said.

Case, 58, said that while the short-term choice is which candidate is best suited to succeed Akaka and deliver in Washington immediately, there is also the potential for generational transition.

"This is not solely about taking over for a specific senator," said Case, who represented the 2nd District for four years until an unsuccessful primary challenge to Akaka in 2006. "This is about representing a state over a long period of time and who can do that best in a changing Hawaii and a changing country."

Case thinks the fiscal stability of the nation is under threat and will make a balanced federal budget a priority in his campaign. He said that his work as an attorney in the business community has given him an understanding of the challenges of meeting payroll and satisfying federal regulations.

"I think we have a key philosophical difference in terms of the role of government," he said. "I think Mazie thinks that government is really the only answer and is always the answer and I believe that government is often the answer but can’t be the only answer."

Case, a moderate, said he thinks voters want their senator to be independent.

"I think that she views the world of Washington as an endless partisan crusade in which the banner of her party is carried aloft into battle and at every turn there are enemies to be slayed," he said. "And I don’t look at the role of government that way today. I really look at our obligation to sit down and get problems solved.

"I don’t think her way is going to work and I think we have to find a different way."

The Democratic primary for Senate crystallized last week when U.S. Rep. Colleen Hanabusa, who had been considering a Senate campaign, said she would run for re-election in urban Honolulu’s 1st Congressional District.

Former Honolulu Mayor Mufi Hannemann is expected to decide soon whether to run for the Senate or in the Democratic primary to replace Hirono in the 2nd District.

After Akaka announced his retirement in March, state Democrats at the highest levels of the party privately talked through different candidates and scenarios, including whether Akaka could be persuaded to step down early so Gov. Neil Abercrombie could name an interim replacement who would have the brief advantage of incumbency. Akaka, however, vowed to fill out the remainder of his term.

Democrats are now making tactical decisions with the understanding that Hirono and Case are the options.

"They represent, certainly, different philosophies," said Dante Carpenter, chairman of the Democratic Party of Hawaii, "but for all intents and purposes I think they have a similar mission."

"And that’s basically to ensure that the Democratic Party platform is upheld at the same time trying to understand that the Congress is a two-party system, and to the extent that you can coordinate, cooperate and get the best benefits for your state, that’s the name of the game."

Carpenter has pledged that the party will remain neutral in the primary, but many establishment Democrats, labor leaders and progressives are aligning behind Hirono.

Labor leaders met privately Wednesday at the International Longshore and Warehouse Union’s headquarters and reached consensus on what participants later described as a "solid front" for Hirono.

"The effort to try to bring all of labor together to try to reach a consensus decision is unprecedented, and to the extent that this will play out and there is consensus reached through everybody’s individual processes, certainly there is a lot of significance to that," said Randy Perreira, executive director of the Hawaii Government Employees Asso­ciation, who also leads the Hawaii State AFL-CIO.

The party’s hierarchy stood with Akaka against Case in 2006, but several senior political strategists believe that even if Hirono were to get similar support, the depth of commitment will not be the same.

Hirono does not have the deep well of aloha that Akaka has with Democrats. The primary is for an open seat, so there is no incumbent to defend on principle. The congresswoman’s high job approval rating — the strongest among Democrats tested in a Hawaii Poll in May — is fragile and not connected to a specific accomplishment.

Case also has sought to repair many of the relationships within the party that were severed by his challenge to Akaka, although underlying distrust remains.

Two Democratic strategists — one sympathetic to Hirono, the other to Case — said privately that while the early momentum behind Hirono is important, many Democrats still have doubts about whether she can defeat former Gov. Linda Lingle, the potential Republican contender, in the general election.

Hirono defeated Case in the Democratic primary for governor in 2002 but lost to Lingle in the general election.

"I am not the same person in 2002 — and that election was very close — and Linda Lingle is not the same person she was when she first ran for that seat," Hirono said, referring to Lingle’s record after eight years as governor. "I’ve learned many, many things and that’s why I won this race for Congress to begin with against very strong Democratic opposition. So I’m going to run a strong campaign to win this race because my message to the people is going to resonate with them. They want somebody who is on their side."

Case said he does not believe Hirono can beat Lingle because he thinks Hirono operates within a "narrow philosophical construct" that does not represent a majority of voters.

"No," he said. "I don’t believe that. I don’t think most people believe it."