By Steven Tavares

Stephen Cassidy declared victory Wednesday evening after the Alameda County Registrar gave the upstart San Leandro mayoral challenger a narrow lead over Mayor Tony Santos in its latest results.

“I said throughout the campaign that the candidate with the most volunteers backing him or her would win. And that proved correct,” said Cassidy, who also thanked his supporters. “This victory is yours as well.”

The results, which the registrar cautions are unofficial, give Cassidy 50.43 percent of the vote after six rounds of tabulation in the new ranked-choice voting system. Santos garnered 49.57 percent, but in a surprise, received the most first-place votes. Late Wednesday, Santos said he pleased to be the top preference of most voters, but plans to explore a possible recount or legal action before the registrar certifies the election Nov. 30.

“Tell him, I’m not conceding anything,” Santos said of Cassidy’s declaration of victory via Twitter shortly after the 6 p.m. announcement.

The debut of ranked-choice voting in Alameda County has not run as smoothly as advocates would like. Oakland’s equally dramatic mayor’s race was also called for the candidate who did not receive the most first-place votes. Oakland Councilwoman Jean Quan, with the help of fellow Councilwoman Rebecca Kaplan, posted a stunning comeback. Don Perata, the former state senator and odds-on favorite, did not make comment Wednesday. Instead, his campaign scheduled a 10 a.m. press conference in Oakland. In many ways, the path Perata takes in challenging the election results may be followed by Santos.

Despite losing in the first round, Cassidy whittled away at Santos’ small lead by winning four of the next five rounds. Councilwoman Joyce Starosciak’s support, or lack thereof, provided the margin of victory for Cassidy. Starosciak supporters broke towards Cassidy by 53-47 percent over Santos, while 1,733 ballots were exhausted before the final round. The registrar also reported 941 undervotes and 78 overvotes that may become the target of any recount by the Santos campaign. By contrast, voters in Oakland casted nearly six times as many ballots as San Leandro residents but amassed 2,798 under and over votes.