As of Saturday, 2,212 people had walked into the registrar's office in Kearny Mesa to cast ballots in the past few weeks, compared to 8,535 in the same period two years ago, Registrar Deborah Seiler said.Of those, 357 came for special early voting hours on Saturday. She said that is also less than the Saturday before Election Day in previous years."This will be a low turnout election," Seiler told City News Service. "I expect about 40 percent."She said figures for 2008 were not applicable for comparison, because primaries were split between February and June. The lack of a competitive presidential primary in either major party was a contributing factor, according to Seiler.Of around 761,000 mail ballots sent to voters, 245,363 had been returned by the middle of Monday, or around 32 percent, she said.The apparent lack of interest comes despite some close races. Four experienced candidates are vying to be San Diego's next mayor, the city has two propositions that pit supporters against organized labor, and two congressional races could be close.Campaigns remained in high gear on the day before polling places open.Councilman Carl DeMaio, the leader in most polls throughout the mayoral campaign, spent the morning visiting retirement homes and planned to spend the rest of Monday and Tuesday working phone banks.Rep. Bob Filner, D-San Diego, whom the most recent survey placed second in the mayoral race, visited senior centers and Veterans Village of San Diego.Assemblyman Nathan Fletcher, who hopes to edge out Filner for a spot on the November ballot, ran in the Rock 'n' Roll Marathon Sunday, and on Monday visited patients at Alvarado Hospital and greeted voters at Hodad's, the popular Ocean Beach burger hangout.District Attorney Bonnie Dumanis appeared on the radio Monday morning and planned to work a phone bank Monday evening.Polls open at 7 a.m. and close at 8 p.m. Tuesday. The first batch of results is expected to be released just after the polls close.San Diego's traditional "Election Central" event at Golden Hall will be held in the evening.