By a 60-40 margin, San Francisco this past Tuesday adopted the strongest anti-Iraq War position yet taken by the voters of a major American city. In supporting Proposition U, they have declared it city policy that its "elected representatives in the United States Senate and House of Representatives should vote against any further funding for the deployment of United States Armed Forces in Iraq, with the exception of funds specifically earmarked to provide for their safe and orderly withdrawal."

Although the measure never drew the kind of attention given to other local ballot questions that variously proposed the legalization of prostitution, raised the prospect of public power, called for renaming the city's sewage treatment plant after outgoing President George W. Bush, and advocated reversing the school board's decision to eliminate the Junior Reserve Officers Training Corps -- or to California initiatives such as Proposition 8 calling for banning gay marriage -- Proposition U did enjoy substantial institutional support. The San Francisco Democratic County Central Committee (the official body of the city's Democratic Party) was an early backer, as was the San Francisco Labor Council.

San Francisco has a history of running ahead of the curve in its opposition to this war. Not only was it the site of some of the country's largest demonstrations in the pre-war period, but in 2004 its voters adopted Proposition N, calling on the federal government "to withdraw all troops from Iraq and bring all military personnel in Iraq back to the United States."

At the time, the domestic fog of war was far denser than it is today. That the invasion of Iraq was a necessary part of a war on terror and the occupation of Iraq represented a humanitarian venture to liberate the country were much more widely held beliefs than they are now. And in that context, Proposition N and its 63 percent vote were cutting edge. Today, a similar measure would likely have won support comparable to the 84 percent Barack Obama enjoyed among San Francisco voters.

Proposition U was designed for a different purpose, though. When one of the city's representatives, the late Congressman Tom Lantos voted for the war, he generally made no bones about disagreeing with the views of his constituents. Speaker of the House Nancy Pelosi, on the other hand, has claimed to be against the war and has been treated by the national newsmedia as a leading antiwar figure, yet has frequently voted to fund it. (California's Senators Diane Feinstein and Barbara Boxer have roughly mirrored Lantos and Pelosi, respectively.) The voters' new position is designed to eliminate any wiggle room on the matter in the future.

Open opposition to Prop U was rare. The Republican Party opposed it, of course. And those who consider the San Francisco Chronicle's editorial board the city's second-most reactionary body found it quite natural that the paper was the only other major institution lined up against. Much more widespread, though, was silence, as figures allied with Pelosi who might even aspire to replace her one day -- like Mayor Gavin Newsom and State Senator-elect Mark Leno -- looked the other way, apparently not interested in making it harder to oppose the war in theory and support it in practice.

It appears that the voters who adopted the policy were quite conscious that this was what exactly what they were doing, however. Certainly the portion of the electorate who showed up on November 4 could not be accused of being frivolous -- 69 percent voted against renaming the sewage plant. And you could not even characterize the day's voting as particularly anti-militaristic, in that 53 percent supported keeping JROTC in the schools.

No doubt many or most of the pro-U voters were elated or at least pleased with Obama's election to replace Bush, yet when given the opportunity to prod the president-elect on his Iraq policy, they took it. For, elation or relief aside, the fact is that Obama's profile on the war has been similar to Pelosi's and his plans call for "combat troops" remaining in Iraq for 16 to 18 months following his inauguration, with tens of thousands of "non-combat" troops staying on indefinitely. (These "non-combat" troops, of course, will remain "non-combat" only until someone attacks them, which seems a rather likely eventuality.) And as his former policy advisor Samantha Power has made clear, this is only a "best-case scenario," and "he will ... not rely on some plan that he's crafted as a presidential candidate."

San Francisco, of course, can do little on its own; Proposition U matters most if it provides any little spark for antiwar voters elsewhere in the country to do something similar. And as we ask ourselves just where the pressure to even stick to a plan to withdraw all "combat troops" by 2010 will come from, the rationale for initiatives like Proposition U may become clear.

The best thing that Barack Obama's supporters could possibly do for him is not to let George W. Bush's war become his war.