Governor

The San Francisco mayor makes the decision amid lackluster poll numbers and meager fund-raising receipts. Atty. Gen. Jerry Brown, expected to run, is left with little Democratic primary opposition.

“At the end of the day, he didn’t resonate,” said David Latterman, a San Francisco political consultant who supported Newsom in both his races for mayor but grew critical in recent months. “The issues he was talking about — high-tech, biotech, green this, environment that — are important. But not for a lot of people at a time the state is a disaster zone.”

Much of Newsom’s campaign was predicated on the notion that he could replicate Barack Obama’s success at riding social-media networks to excite young voters and attract other normally inattentive Californians. He worked hard to build the state’s most expansive electronic grass-roots operation. He raised money online. His events were organized via Facebook. He was a regular on Twitter, even from his wife’s bedside immediately after she gave birth.

Ultimately, however, none of that translated into broad success or financial support for the first-time statewide candidate. A Field Poll released earlier this month showed Newsom far behind Brown, who, at least publicly, all but ignored his challenger. The attorney general had the support of 47% of Democratic voters, compared with just 26% for Newsom. The only voters among whom the mayor was leading were those 18 to 39 — some of the least likely to turn out. With them he had a 9% advantage.

More important, Newsom trailed badly in the money chase. He had $1.2 million in the bank at the end of the last reporting period in June and had raised only $709,000 since. Brown had $7.4 million on June 30 and has raised $1.3 million more since.

Earlier this month, Newsom brought in former President Clinton, an old Brown nemesis, for an endorsement and fund-raising event. But the returns, at least as indicated by partial financial reports, were disappointing.