Rod Tam, a former Honolulu councilman and state lawmaker who five years ago pleaded guilty to 26 misdemeanor and petty misdemeanor counts of theft and falsifying documents, is now attempting to make a political comeback as a Republican.

Tam, 62, filed Monday to run for the open District 13 state Senate seat, which includes Downtown Honolulu, Nuuanu, Iwilei and Liliha. That seat is being vacated by longtime Democratic Sen. Suzanne Chun Oakland, who has announced she will not run for re-election this year.

Tam was elected as a Democrat to the state House from 1982 to 1994 and to the state Senate from 1994 to 2002. He was elected to the City Council in 2002, where he remained until he made an unsuccessful bid to become Honolulu mayor in 2010.

Late in his time in office, Tam became publicly entangled in investigations into alleged misconduct, and in 2011 the court ordered him to serve two days in jail and 300 hours of community service after pleading guilty in June of that year to the 26 misdemeanor and petty misdemeanor counts.

Those charges were related to overcharging the city for meals at Honolulu restaurants from 2007 to 2009.

Tam pleaded no contest to eight misdemeanor counts of violating campaign spending laws by falsely claiming he had a meal with a volunteer at a restaurant, failing to report two campaign contributions, misusing campaign funds and failing to maintain receipts to verify expenses.

In March 2010 the Ethics Commission fined Tam $2,000 and ordered him to pay $11,700 in restitution for using city funds to buy “hundreds” of meals totaling more than $22,000 unrelated to his city work.

In 2012 the Ethics Commission fined Tam $813.53 for misusing city funds to buy appreciation lunches for city employees and for a Chinese dinner for foreign delegates. Those cases dated back to 2009 and 2010.

Tam refused to discuss his attempt at a political comeback Tuesday when reached by telephone, and said all media requests for comment would be routed through his campaign manager. He also refused to discuss his decision to run as a Republican.

Hawaii Republican Party Chairman Fritz Rohlfing acknowledged Tam’s “legal troubles” but said Tam’s record was cleared after he entered his pleas and complied with requirements imposed by the courts.

“He has a clean record now, so I think it’s time for him to come back, and a lot of people in his community have asked him to do this, and we’re grateful that he has the values that we have, and he wants to promote the Republican values,” Rohlfing said.

“We are thrilled that he’s coming over,” he added. “He’s a grass-roots guy, he’s close to his community. I think he’s a really strong campaigner, so we’re looking forward to that.”

Also running for the District 13 Senate seat are state Rep. Karl Rhoads, 53, who is now chairman of the House Judiciary Committee, and former Board of Education member Kim Coco Iwamoto, a member of the Hawaii Civil Rights Commission. Both are Democrats.

Keone John Nakoa, a Democrat, and Harry Ozols, a Libertarian, have also filed to run for the Senate seat.