Adithya Sambamurthy/The Bay Citizen

Zynga employees arrive at the headquarters of the San Francisco start-up on Thursday, June 9, 2011

In late March, Supervisor Ross Mirkarimi of San Francisco met with lobbyists from Zynga, the online gaming giant, and agreed to introduce a bill to eliminate the city’s unusual tax on corporate stock options.

Mirkarimi’s legislation, which was signed into law June 3, could save Zynga $30 million to $50 million in local taxes in the first year alone if, as expected, the company goes public at a multibillion-dollar valuation. Other San Francisco start-ups on the verge of initial public offerings, including Yelp and Twitter, had also sought a repeal of the tax.

On May 20, three days after the Board of Supervisors passed the bill, a lobbyist from Platinum Advisors, the firm representing Zynga, organized a breakfast fundraiser for Mirkarimi’s campaign for sheriff at a bistro in the Ferry Building. The event brought in about $3,000, Mirkarimi’s aides said.

The fundraiser does not appear to violate San Francisco’s intricate but erratically enforced lobbying laws, and political operatives say such events are common. Still, the breakfast and its timing offer a glimpse into the confusing intersection of politics and government in San Francisco, a system dominated by a few powerful lobbying firms that provide elected officials with the cash and connections they need to survive politically.

In an interview, Mirkarimi rejected the notion that the fundraiser influenced his decision to push legislation proposed by Platinum Advisors.

“I haven’t received any contributions from Zynga or them,” he said, referring to Platinum. “I don’t see a problem.”

Chris Gruwell, the president of Platinum’s San Francisco office, said he paid for the breakfast out-of-pocket as a private Mirkarimi supporter. The fundraiser was not related to the tax legislation, he said, and Zynga played no role in organizing the breakfast.

Ethics questions surrounding lobbyists’ relationships with candidates have become a major issue in the early months of this year’s mayoral election. In May, Alex Tourk, a political consultant, resigned from the mayoral campaign of City Attorney Dennis Herrera after disclosures that he had lobbied Herrera while managing his campaign, which is prohibited by city law.

Several days later, The Bay Citizen reported that Herrera had been lobbied by Samuel Lauter, a lobbyist from his remaining campaign consultant, Barnes Mosher Whitehurst Lauter and Partners, on behalf of a Georgia energy company in 2009 while Mr. Lauter’s business partner, John Whitehurst, ran Mr. Herrera’s re-election campaign for city attorney.

Whitehurst has since said that the apparent violation was due to a clerical error and that his firm kept its lobbying and campaign practices strictly separate. Lauter has continued to raise money for Herrera as he now runs for mayor, the San Francisco Examiner reported.

While lobbyists moonlighting as fundraisers are a fact of political life from Washington to Honolulu, they play an outsized role in San Francisco, a small-town political fishbowl with a concentration of big-money interests.

“Political fundraising is something that is regularly done by almost all interested parties in politics in San Francisco,” said Alex Clemens, the founder of Barbary Coast Consulting and an active fundraiser for public officials. “In our town, elected officials, candidates and political consultants all know the rules, report their activities and keep things transparent.”