However, Cooley didn't actually concede in person -- his campaign phoned it in.
On election night, Cooley declared victory in the race for state attorney general, but on Wednesday when it became clear that the late vote count had turned against him, he didn't show up to concede in person, his campaign chairman held a conference call.
"He did call the district attorney and frankly congratulated her personally, he's at the office, he's working. He was not willing to neglect his responsibilities there," said Kevin Spillane, Cooley's campaign manager.
Harris declined to publicly declare victory and instead she issued a statement saying, "It is only appropriate to wait until all the votes are counted before making a public declaration," said Harris.
She has scheduled a news conference next Tuesday.
Meanwhile medical marijuana groups that campaigned against Cooley are celebrating.
"Americans for Safe Access is absolutely thrilled, we're ecstatic," says Laura Payne, legal coordinator for the medical marijuana advocacy group Americans for Safe Access.
Payne says Harris' win, by just one half of 1 percent is largely due to medical marijuana patients, who saw Cooley as a threat to their supply.
"He has hosted huge conferences entitled 'How to Eradicate Medical Cannabis From Your Community,'" says Payne.
Frank Lee, the Bay Area director of the campaign against legalizing marijuana, says he voted for Cooley but he doesn't think Harris will give medical pot dispensaries or marijuana growers a pass.
"We believe it's premature to predict what Ms. Harris will do for California," says Lee.
Lee points to U.S. Attorney General Eric Holder's warning that the federal government will continue to enforce federal marijuana laws and Lee feels Harris will align herself with a larger constituency.
"We believe she understands that San Francisco is different from California. Now with that understanding, hopefully she will tighten up a little bit in this aspect when she works for California," says Lee.
Harris' election could set off an interesting chain of events at San Francisco City Hall. If she resigns early, Mayor Gavin Newsom would appoint her successor, and if he were to choose a progressive on the Board of Supervisors for her post as district attorney, it could make it easier for the mayor to orchestrate the selection of his own successor as mayor, when he becomes lieutenant governor.