U.S. Rep. Mazie Hirono contends Hawaii voters want a U.S. senator who shares their values, who is tough enough for a fight but practical enough to collaborate.

When the liberal congresswoman speaks about values, she does not mean the left or right politics of Washington, D.C., but the examples she learned from her mother, who fled an abusive husband in Japan to bring her children to the islands. She means education that unlocks the opportunity for children to succeed, jobs that pay a living wage, and a safety net strong enough to take care of seniors.

In the Democratic primary against former Congressman Ed Case, a moderate who has challenged Hirono to move beyond her biography, Hirono has relied on her immigrant story to explain to voters why she would be on their side if chosen to replace retiring U.S. Sen. Daniel Akaka.

"My background has so much to do with the fact that I don’t give up, that I’m very focused, because I had a mom who did that," Hirono, an attorney, said in an interview at her campaign headquarters off Nimitz Highway. "I’ve told her that there’s nothing I can do that will ever match what she did in terms of her personal courage."

Hirono, 64, describes Case, who is known for his independence, as more likely to alienate lawmakers in Washington than collaborate.

"You can be the smartest person, but you’re not going to accomplish much if you can’t work with your colleagues and if you can’t convince your colleagues of what you’re doing," she said.

U.S. Sen. Daniel Ino­uye, the state’s leading Demo­crat, and the Demo­cratic Senatorial Campaign Committee prefer Hirono in the primary. Most of the labor, environmental and progressive interests that dominate party politics have endorsed her. She has eclipsed Case in fundraising. Her campaign team is stocked with advisers who helped Akaka beat Case in a primary six years ago.

But below the surface, many political insiders still have suspicions about her abilities as a campaigner, citing a coolness for the retail side of politics that sometimes comes across as disdain. After three decades in elected office as a state legislator, lieutenant governor and congresswoman, her critics say, voters should know more about her than her childhood struggle with poverty.

"Mazie can’t win," the refrain that undermined her campaign for governor against Linda Lingle a decade ago, is creeping into conversations about a potential rematch with the Republican in the November general election.

Amy Agbayani, who directs diversity programs for students at the University of Hawaii at Manoa, said Hirono’s biography has influenced the congresswoman’s approach to issues such as protecting Social Security and Medicare and advocating for universal preschool. She believes Hirono’s public service is an attempt to help people living through the experiences she had as a young girl.

"She picks the right issues to fight about," she said.

Agbayani said Hirono, as a liberal woman representing the same rural Oahu and neighbor island congressional district as the late U.S. Rep. Patsy Mink, a feminist icon, was expected to carry on Mink’s legacy. Even before going to Congress, she helped form the Patsy T. Mink Political Action Committee to elect progressive, pro-choice women to state office, the steppingstones for national politics.

But Hirono, as she did on policy issues at the Legislature, has also quietly dug into the grunt work necessary to win federal money for Hawaii.

"If you look at her track record, she actually delivers," Agbayani said. "And that’s because she has the collaborative style."

Hirono’s record in the state House, where she represented McCully and Moiliili, was labor and consumer oriented but occasionally more strident than collaborative. She wanted government to ensure that developers included affordable housing in their projects, taxed real-estate speculators who were driving up housing prices and compelled auto insurers to roll back premiums.

As Gov. Ben Cayetano’s lieutenant governor, she supported the state’s creation of the Hawaii Employers’ Mutual Insurance Co., a workers’ compensation insurer of last resort for businesses. (Hirono named her pet cat "HEMIC.") She celebrated the Pre-Plus early education program for children from low-income families. She lobbied Congress to include South Korea in the federal visa-waiver program so more Korean tourists could visit the islands.

While publicly loyal to Cayetano, Hirono maintained some autonomy, walking the picket line with public school teachers and urging a fair contract settlement with the state during a strike in 2001.

IN CONGRESS, Hirono was in the majority for her first four years, the minority her last two, and has gone through the same challenges as other junior lawmakers in sculpting individual accomplishments in a 435-member chamber.

Hirono takes pride in achievements that might not make banner headlines but are important to communities. Among them were $2 million that Wai­ma­nalo residents wanted to help clean up a World War II-era landfill at Marine Corps Training Area Bellows; repair money for the Lower Hama­kua Ditch to help provide irrigation water for farmers and ranchers in Hawaii County; and an additional $6 million annually after getting the Federal Aviation Administration to count interisland passengers in the formula for awarding airport improvement grants.

Hirono was also aggressive about setting up Hawaii to receive federal money through earmarks — a tool Ino­uye has used successfully in the Senate — before House Republicans curtailed the practice. According to the Center for Responsive Politics, Hirono ranked first in the House for sponsoring or co-sponsoring earmarks in fiscal year 2010 and fourth in fiscal year 2009.

"I truly am a doer," she said. "I am not a talker."

Hirono had a liberal rating of 90.7 this year, which places her among the most liberal in the House, according to the National Journal, which publishes annual ratings of federal lawmakers. Case, who served in the Blue Dog Coalition of moderate and conservative Demo­crats, had a 59.8 liberal rating in 2006, which is closer to the ideological middle.

Hirono and Case have similar views on social issues and the environment but splinter on economic policy. As a member of the Congressional Progressive Caucus, Hirono is more vocal than Case about calling for higher taxes on the wealthy, ending tax breaks for oil companies and reducing national defense spending.

But often their differences are more about emphasis. Hirono and Case both favor a millionaire’s tax and ending tax cuts for the wealthy approved under President George W. Bush. Both Demo­crats would lift the $110,100 cap on earnings covered by the payroll tax that finances Social Security. Hirono, however, would set the income cap higher than Case, shifting a greater share to the wealthy, while Case would also raise the retirement age for younger workers to help sustain Social Security over time.

"I don’t think people in Hawaii even know what a Blue Dog person is," Hirono said. "Truly, they don’t think about things in that way. They think about who is really listening to them, who is on their side, who is getting things done for them."

Case has consigned Hirono to the left-wing fringe, outside the mainstream in Hawaii and Washington. But the Progressive Caucus, at 75 House members, is the largest among Demo­crats and three times the size of the Blue Dog Coalition.

Patrick Griffin, a professor at American University in Washington, D.C., who served as a White House assistant on legislative affairs under President Bill Clinton, said the caucus more closely reflects the politics of leading liberals such as House Minority Leader Nancy Pelosi, D-Calif.

"To call it fringe would be an exaggeration," he said. "It’s probably more aligned with the mainstream of the leadership of the congressional caucus."

Hirono dismisses comparisons between this election and the 2002 governor’s race, when she barely escaped a primary against Case and lost to Lingle. Pay-to-play scandals had weakened Demo­crats to the lowest point since statehood. Hirono appeared indecisive when she bypassed the governor’s race for a campaign for Hono­lulu mayor, then jumped back in after Mayor Jeremy Harris, the party’s favorite, backed out of the governor’s race in the cloud of a campaign-finance investigation.

(Cayetano, in his 2009 memoir, said he was officially neutral in the primary. "It was no secret, however, that I was pulling for Case to win.")

Lingle made state history as the first woman and the first Republican in 40 years to be elected governor.

"She knows that the people of Hawaii remember Furlough Fridays, remember the fiasco over the Superferry and the fact that she was out there campaigning for the McCain-Palin ticket," Hirono said of Lingle’s two terms.

Hirono would make her own history this year. She would be the first Asian-American woman and just the third woman of color ever elected to the U.S. Senate.

"Every time I talk about my background, my mom and her influence on my life and my values, people always come up to me," she said. "It doesn’t matter whether it’s here or on the mainland. They say, ‘You know what? You really get what people are going through, what our family is going through.’

"And, in fact in my life, so many people come up to me in my life, they’ll say, ‘I had a situation like that. And it’s very important that somebody like you, with that kind of experience and voice, is in the U.S. Senate.’"