Interim Mayor Ed Lee is poised to win San Francisco’s mayoral race handily, according to results of a Bay Citizen/USF Poll that shows Lee dominating his main rivals and ultimately cannibalizing their votes under a format that requires voters to rank the candidates by preference.

Lee, 58, a career bureaucrat who until January had never held office, would become San Francisco’s first elected Chinese mayor. The poll highlights the growing power of the city’s Chinese community, which now comprises one-fifth of the electorate and is increasingly flexing its political muscle.

Gerry Shih/The Bay Citizen

San Francisco Mayor Ed Lee speaks to supporters outside City Hall on Oct. 11, 2011

Three weeks before the Nov. 8 election, Lee is the overwhelming choice of Chinese voters and the favored candidate of LGBT voters, according to The Bay Citizen/USF Poll, the most extensive independent survey of San Francisco voters during this election.

This is the first competitive San Francisco mayoral race to employ ranked-choice voting. The Bay Citizen/USF Poll indicates that Lee’s support is so deep he will benefit handsomely from the format.

More than 31 percent of respondents said Lee was their first choice, while only 8.1 percent chose his closest rival, City Attorney Dennis Herrera. The poll found that John Avalos, the liberal supervisor from the Excelsior District, who has the endorsement of San Francisco’s Democratic Party, was the top choice of 7.4 percent of respondents. State Sen. Leland Yee, once considered a leading contender, earned only 6.5 percent of first-place votes.

More than a fifth of likely voters — 21.1 percent — remain undecided, the poll showed.

Under the ranked-choice system, voters choose their top three candidates in order of preference. The candidate with the fewest first-place votes is eliminated, and the second choices of the voters who selected that candidate as their first choice are distributed to the remaining contenders. The process is repeated until one candidate exceeds 50 percent.

A Bay Citizen simulation based on the poll results estimated that Lee would triumph after nine elimination rounds. The simulator can be viewed here:

The elimination process on Election Day may well unfold differently. The poll asked respondents for their views on 11 of the 16 candidates who appear on the ballot.

Lee’s advantage is overwhelming and possibly insurmountable, according to Corey D. Cook, director of USF’s Leo T. McCarthy Center for Public Service and the Common Good, who helped administer the poll.

“Lee’s the clear-cut first choice, but he’s also getting second-place votes from everybody,” Cook said. “No contenders have a chance to catch him in the subsequent tallies — he just wins.”

In addition to his 23-point advantage in first-place votes, Lee claimed more second-place votes (10.8 percent) and third-place votes (6.8 percent) than any other candidate in the poll. Among Chinese voters, he swept 57.3 percent of first-place votes in the poll; Yee was a distant second at 7.7 percent.

Herrera and Yee laid the groundwork for their mayoral campaigns years ago. Despite spending more than $1 million each, both have sputtered since Lee entered the race Aug. 8.

When the Board of Supervisors named Lee interim mayor in January, after former Mayor Gavin Newsom was elected lieutenant governor, Lee promised not to run for a full term. But after two of his biggest political supporters — Rose Pak, the powerful Chinatown lobbyist, and former Mayor Willie Brown — led an effort to draft him into the race, Lee changed his mind.

That reversal does not appear to have hurt Lee, and neither have allegations of ethical misconduct by some of his supporters. To the contrary, his entrance into the race seems to have energized Chinese voters.

Roughly 85 percent of Chinese respondents approved of Lee’s job performance, according to the poll, a figure that exceeded even the 76 percent approval rating he has among voters who are not Chinese.

And 40.2 percent of Chinese respondents said they had been following the mayoral race “a lot” compared to 24.7 percent of non-Chinese voters.