"It was a lot of hard work," said Case, who sees himself as part of a new generation of Hawai'i political leaders. "I was taking the place of someone who was revered in this district."

Incumbents in Congress are usually the most vulnerable during their first re-election campaign, before voters have grown familiar with their leadership style and they have yet to build the fund-raising prowess that can scare off rivals. In Hawai'i, no incumbent who has served a full term in Congress has lost a re-election campaign.

Mike Gabbard, a Honolulu city councilman running against Case, hopes to break that pattern.

Gabbard, best known for his support for traditional marriage, has raised $398,000 and has had a strong presence with TV commercials and campaign signs throughout the district. Case, who had initially trailed Gabbard in fund raising, has collected $632,000 for his re-election campaign.

"I'm a fighter," Gabbard said. "I do my homework and I get behind something and I fight."

Some political analysts have described Gabbard as a single-issue candidate who lacks the broad support needed for a congressional race. But Gabbard has been underestimated before and has proven capable of doing the groundwork necessary to be successful.

Tom Coffman, author of "Catch A Wave: A Case Study of Hawai'i's New Politics," sees Gabbard as part of the growing influence of religious conservatives on Republican politics in Hawai'i.

Gabbard's supporters have targeted churches, passing out literature that describes Gabbard as a practicing Catholic who would represent people of faith better than Case, a Protestant.

Coffman said it was telling, and likely a mistake, that Gabbard himself brought up same-sex marriage in television ads over the past few weeks after trying to widen his appeal earlier in the campaign. "It's the tiger and his stripes," he said.

Case, a former state lawmaker who ran unsuccessfully for governor in 2002, has surprised some analysts by engaging Gabbard with debate challenges and public e-mail critiques, since many incumbents minimize or simply ignore their opponents unless the campaigns are close.

But Case's nature is to be aggressive.

While he has sought to fit in with the three other Democrats in the Hawai'i delegation, particularly with U.S. Sen. Dan Inouye, the state's most influential politician, Case has sometimes broken out on his own.

Case said he would continue to work for a Hawai'i exemption to the Jones Act, a federal law that requires cargo ships operating between domestic ports to be U.S. flagged and crewed. The congressman says the 1920 law, passed to protect the American shipping industry, has given Matson Navigation and Horizon Lines a monopoly in Hawai'i that costs consumers through higher prices for goods. Foreign competition, Case believes, could lead to greater options for exporters and lower consumer costs.

But Inouye opposes the exemption, and shipping officials have said it could undermine a strong and reliable shipping link between Hawai'i and the Mainland.

"I will not stop that effort," Case said. "I do not support a government-created monopoly."

Gabbard said the exemption would be "irresponsible and shortsighted."

"I think it would be a big mistake," he said.

In Hawai'i, Case has disagreed with Democrats who oppose breaking up the state Department of Education into local school districts with elected school boards. The congressman offered to help Gov. Linda Lingle on the issue even after it became apparent that the school board question would be the political dividing line between the Republican governor and Democrats last session.

As a first-term Democrat in the Republican-controlled House of Representatives, Case's influence on major legislation is limited and, like all new members, he has had to adjust to a process that often rewards seniority and power over new ideas. Case is in step with the other Hawai'i lawmakers on the key issues for the state —the military, tourism, drug-abuse prevention and Native Hawaiian federal recognition — but he is generally more of a moderate.

He takes pride in being open and accessible and he and his staff have placed an emphasis on constituent casework, a rarely discussed yet important aspect of a congressman's job.

Case has made it clear that he is interested in moving up to the Senate one day, and many analysts view him as a long-term rival to Lingle in Hawai'i politics. "I believe that I am part of the generation beyond the one that has served us so well," he said.

Both Case and Gabbard agree that improving public education is a priority for Hawai'i and believe states should get more federal money and greater flexibility to meet the federal No Child Left Behind Act. The law requires schools to make annual progress toward having all students proficient in core subjects by 2014.

Case serves on the House Education and the Workforce Committee and could have a role in any changes to the law. "The concept of the law is sound. It's the implementation of the law that's the problem," Case said. "It's a perfect example of Washington's one-size-fits all thinking."

Gabbard said he also wants to dramatically downsize the U.S. Department of Education and get more federal education money and power to the states. Republicans, when they first took control of the House a decade ago, wanted to abolish the Education Department, but No Child Left Behind has given the federal government more authority over education policy.

Both candidates also want to lower the federal budget deficit, control government spending and reduce taxes and regulations on small businesses.

"I think we're already overtaxed as individuals and small businesses," Gabbard said.

Case said he wants to help small businesses compete more in agriculture, information technology and federal procurement. "Small businesses are the only businesses in my district," he said.

But the candidates are deeply divided on social issues, particularly same-sex marriage.

Gabbard was among the leaders of a successful 1998 campaign for a constitutional amendment that defines marriage as between a man and a woman. Hawai'i voters overwhelmingly approved the amendment, and national opinion polls show that most people oppose gay marriage, but Gabbard and his family have been called extremists by gay-rights activists and by some in the media.

The experience has made Gabbard often gun-shy around reporters and left some on his staff preoccupied with media bias.

Same-sex marriage has been an issue nationally in the presidential campaign and, given Gabbard's history, was always going to have an impact on his congressional race.

Gabbard describes marriage as the "foundation of civilization" and considers the issue extremely important, but not the only subject he cares about or would work on if elected. He has not used his seat on the City Council as a platform to oppose gay rights.

Gabbard said he favors a federal constitutional amendment banning gay marriage to take the issue away from interpretation by state and federal courts. "I don't trust the judges," he said. "I trust the people."

Gabbard has criticized Case for opposing the Hawai'i amendment and for voting against a federal constitutional amendment when it came before the House this year.

"Ed's an elitist who believes that judges and lawyers should be making the decisions," Gabbard said.

Case said he is not an advocate for same-sex marriage but does not oppose it and does not regard homosexuality as a sin. He said he respects Hawai'i's diversity and does not believe that any one set of religious beliefs should be imposed on people.

But he said it would be an "invitation to disaster" for someone like Gabbard to represent the district in Congress. "This is, to my opponent, an obsession, not a difference of opinion," Case said.