Democrat Scott Peters on Friday won a second term to represent a large swath of San Diego in Congress following a bitter campaign that saw his Republican challenger on the defensive against accusations of sexual harassment by a former campaign staffer.


Peters led with 51.3 percent of the vote compared to 48.8 percent for Carl DeMaio, a 4,491-vote lead. Although San Diego County Registrar of Voters Michael Vu estimated that between 10,000 and 15,000 ballots remained to be counted, The Associated Press determined that is insufficient for DeMaio to overtake Peters.


Peters, 56, returns to Congress after his second close election to represent a district where Republicans hold a slight edge in voter registration. The moderate Democrat and former San Diego city councilman sought to portray his opponent as a captive of the Tea Party.


DeMaio, 40, would have been a rarity in Congress as an openly gay Republican. DeMaio said his party needed to become more inclusive, prompting some prominent opponents of same-sex marriage to back Peters because they worried DeMaio would be a more formidable adversary. Many leaders of the gay community also backed Peters.


DeMaio was dogged by allegations of sexual harassment during the last month of the campaign. Todd Bosnich, his former campaign policy director, claimed that DeMaio sexually harassed him and that he was offered $50,000 to stay quiet.


DeMaio said he suspected Bosnich of a campaign office burglary during which computer screens were smashed, phone lines cut and a campaign strategy book stolen. He said he fired Bosnich for plagiarizing a report on congressional pensions.


San Diego County District Attorney Bonnie Dumanis said little more than two weeks before the election that there was insufficient evidence to file criminal charges against DeMaio or Bosnich, but controversy surrounding DeMaio fueled news coverage. DeMaio sought to bring attention to issues ranging from veterans benefits to border security but was repeatedly confronted with the allegations.


DeMaio, also a former San Diego city councilman, ran a strong campaign for mayor in 2012 by pledging to fix pensions and potholes but lost to Democrat Bob Filner, who resigned after less than nine months in office amid a torrent of allegations that he sexually harassed women. Filner was sentenced to three months of home confinement after pleading guilty to felony false imprisonment and two misdemeanor charges of battery.


DeMaio flirted with another run for mayor to replace Filner but stayed in the congressional race after some Republican leaders backed Kevin Faulconer, a more mild-mannered city councilman who went on to win.


Ballots that were mailed in shortly before the election tilted heavily for Peters. DeMaio held a lead of a less than one percentage point on election night but was overtaken Thursday with a batch of ballots that leaned 56 percent to 43 percent in Peters’ favor. Friday’s update leaned even more for Peters.


Peters’ campaign manager, MaryAnne Pintar, said the campaign was “thrilled” with Friday’s update. DeMaio spokesman Dave McCulloch had no immediate comment.


California’s 52nd congressional district spans much of San Diego’s coast and includes the suburbs of Poway and Coronado.