By Marty Graham
SAN DIEGO (Reuters) - Voters in California's second-largest city will choose from among 11 candidates vying to succeed former San Diego Mayor Bob Filner in a special election on Tuesday, less than three months after he resigned in the face of a sexual harassment lawsuit.
With none of the candidates likely to clinch the majority vote needed to win outright, the officially non-partisan race is expected to set the stage for a run-off between the leading Republican contender, City Councilman Kevin Faulconer, and one of two Democrats expected to battle it out on Tuesday for second place.
"This will be a low-turnout, single-issue election, and there won't be a candidate who ends up with 50 percent of the vote," said Carl Luna, a political science professor at San Diego Mesa College. "The race for mayor will come down to who comes in second."
San Diego, the nation's sixth most populous city, has long voted conservative, in part because of its large military and retired military presence.
But the outcome of the special election will be shaped by the growing clout of Hispanic voters, particularly in southern San Diego, an area whose population and concerns went largely ignored until voters there last November helped make Filner the first Democrat elected as mayor in two decades, experts say.
Two Democratic candidates appeared most likely to face Faulconer in a runoff election in February.
One is former U.S. Marine and onetime state Assemblyman Nathan Fletcher, who was a Republican before switching parties after finishing third in the 2012 mayoral race. With the backing of several key labor unions and the high-tech industry, Fletcher had been seen as the presumptive Democratic nominee.
Although he started the campaign with nearly 40 percent popular support, polls show Fletcher has steadily lost ground to City Councilman David Alvarez, who has gained the endorsement of the San Diego Democratic Party.
Alvarez, whose platform most resembles Filner's, was elected to the City Council in 2010 by the largely working-class and strongly Hispanic neighborhoods south of Interstate 8, including Barrio Logan, where he grew up.
He has established a track record of fighting for those communities, often finding himself at odds with the downtown establishment that backs Faulconer.
"The issues the candidates are talking about are neighborhoods, job creation and cops," Luna said.
Filner, who served in Congress for 20 years before he was elected mayor in 2012, resigned at the end of August as part of a settlement with the city over how to handle a sexual harassment suit filed by his former press secretary, Irene McCormack Jackson.
She was one of 19 women who came forward to accuse the 70-year-old politician of making unwanted advances toward them.
The scandal that ended Filner's political career has scarcely been mentioned in the recent campaign, though the candidates do make frequent references to integrity, character and openness in city government, Luna said.
Steven Erie, a political science professor at the University of California at San Diego, said he sees Fletcher as the Democrat with the widest appeal, "and that scares the heck out of the downtown crowd because he's the candidate who can beat Faulconer."
"David Alvarez may not be ready for prime time this election, but he is the face of the future of San Diego politics," Erie said.
In a bit of political gamesmanship, Alvarez has received unsolicited support from the largely white Republican Lincoln Club, which paid for a series of mailers favorably comparing Alvarez to Fletcher.
"Their game is to force a runoff between Faulconer and Alvarez because they're scared that Fletcher can actually beat Faulconer and they believe Alvarez can't," Erie said of the Lincoln Club's political stance.
(Editing by Steve Gorman and Eric Walsh)