Cambridge’s 34 candidates for City Council and School Committee go into Tuesday’s elections with the largest number of voters in more than a decade.

There are 70,602 voters registered in the city – a 25 percent jump from 2005, before Barack Obama energized the electorate by running for president, but also an 18 percent jump from 2009 and a 17 percent jump from the 2011 municipal elections.

“The increase is partially due to increased voter registration from the 2012 presidential election,” said Lesley Waxman, assistant director of the city’s Election Commission in a Monday e-mail. The figures are also “partially due to voter registration for the special elections and tomorrow’s election, and partially due to the fact that we could not do our usual deletion of voters this year due to the number of special elections.”

Waxman

Voters who have been inactive for two federal election cycles are normally deleted, Waxman said, but state and federal law says there can be no automated deletion within 90 days of an election.

“And we were always within 90 days of an election this year,” she said.

There was an April 30 primary leading to a June 25 special election in which Ed Markey beat Republican Gabriel Gomez for a U.S. Senate seat, then an Oct. 15 primary to determine that Democrat Katherine Clark and Republican Frank Addivinola will vie Dec. 10 to fill Markey’s seat.

Another factor in the large number of voters: Registered voters at Harvard got a bump from last year’s Elizabeth Warren-Scott Brown race for U.S. Senator. An analysis today by Harvard Crimson staff writer Sonali Y. Salgado said there were 994 votes cast in Cambridge by people in Harvard dorms, a significant jump from the 385 seen in 2008.

City Council candidate Logan Leslie has been working on getting out the vote at Harvard, where he is pursuing an advanced degree. Salgado quoted an e-mail sent by Leslie to Harvard students in which he tells them“I’m running to begin a conversation between students and our city’s leaders” and tells them their votes will “truly make a difference.”

There could also a jump in registered voters from the sheer number of candidates. Having 25 people run for council is a 40 percent increase from last year’s 18, although the number of people running for committee has dipped slightly, to nine from 11.

Robert Winters, the mathematician and educator behind the Cambridge Civic Journal website, believes voter rolls in the notoriously transient population of Cambridge (where Census data have said more than a quarter of the population is in college) are swollen with people who may have left the city long ago – and with people who simply don’t go to the polls. In 2011, looking at official voter turnout of 26.5 percent, he thought a more accurate estimate was about 34 percent of actual voters.

The average turnout over the past four council elections has been 26.7 percent of all registered voters, according to data provided by Waxman. (For School Committee races, it’s a barely noticeable difference: 26.6 percent of registered voters.)

The 2007 elections had the lowest turnout dating back at least to the 1990s. With 13,721 ballots cast from among 55,571 registered voters, turnout that year dipped to 24.7 percent.