Former Mayor Mufi Hannemann has taken the fundraising lead in the race for Hawaii’s 2nd Congressional District, but his rivals kept pace in the last quarter of 2011.

Hannemann’s campaign reported Friday raising $538,000 in the race overall, including more than $231,000 in the last three months of last year.

Honolulu City Councilwoman Tulsi Gabbard previously reported raising $203,000 in the last quarter and $352,000 for the campaign to date. Big Island attorney Bob Marx’s report filed with the Federal Election Commission shows he raised $214,000, including $50,000 of his own money.

Former Office of Hawaiian Affairs Chief Advocate Esther Kiaaina has raised $23,000 through the end of September. Her most recent report was not available Friday. Honolulu attorney Rafael del Castillo also had not filed.

The filing deadline for fundraising in the last quarter of 2011 is Monday.

Candidates are seeking to succeed U.S. Rep. Mazie Hirono, who is running for U.S. Senate, to represent rural Oahu and the neighbor islands.

Neal Milner, retired University of Hawaii political science professor, pegged Hannemann as the favorite in the race, but said Gabbard could be a tough challenger.

“It’s kind of a classic race against a well-established, experienced candidate and office older against somebody who’s held office, but is relatively new and not very well known yet district-wide,” Milner said.

Each has obstacles to overcome.

“I think what adds a dimension to the race is the fact that I think Hannemann, on the basis of his last race, is somewhat of a flawed candidate,”?Milner said. “The things he did that he thought were going to get him elected  really backfired.”

Hannemann was twice elected as mayor with strong backing from business and labor groups, but was soundly beaten by Gov. Neil Abercrombie in the Democratic Primary for governor in 2010, losing 60 percent to 38 percent, His favorability dropped after backlash from a flier that asked voters to compare where the candidates were born, their wives and their education.

“The tricky thing about this campaign for Hannemann, and the opportunity maybe for Gabbard, is that Hannemann is not all that popular among the kind of Democrats who are most likely to vote in the primary,” Milner said. “I think there’s a bit of a distrust there — not a great history — and he can’t make the argument so easily that he’s so stong that he’s a winner.”

Gabbard, Milner said, must overcome the shadow cast by her father, state Sen. Mike Gabbard, a Republican-turned-Democrat who remains a strong conservative on social issues.

“Even though she gets associated with her father on these very socially conservative positions on issues involving gays, but she’s attempted to get out from under those positions and has gotten some national feminist organization endorsements,”Milner said. “She’s managed to make some inroads for a newcomer that are fairly impressive.”

Gabbard has been endorsed by the Women Under Forty Political Action Committee. A former state representative who is in her first term on the City Council, Gabbard also is a veteran of the wars in Iraq and Afghanistan and has been endorsed by VoteVets.org, a political action committee dedicated to veterans’ interests.

Hannemann has been endorsed by labor unions including the United Public Workers and the Hawaii Construction Alliance, a group of construction unions with a combined membership of about 15,000.