Grassroots gay activists protesting the passage of California's gay marriage ban on November 4 turned their attention Saturday to the federal-level ban.

The federal Defense of Marriage Act, widely known by its acronym DOMA, is the 12-year-old law that defines marriage as a union between a man and a woman for federal agencies and allows states to ignore legal gay marriages performed in another state.

Former Georgia Representative Bob Barr (Republican turned Libertarian) authored the legislation and former President Bill Clinton (Democrat) signed it.

A march in downtown San Diego started at 10AM at the San Diego County Administration building.

The federal-level protest is a transformation of sorts for grassroots activists who had remained focused on the ins and outs of passage of Proposition 8 – the California constitutional amendment that not only banned gay marriage but also put a stop to gay wedding celebrations occurring in the state. Of the 29 constitutional gay marriage bans in America, only blue California has revoked the right of gay and lesbian couples to marry.

About 18,000 gay couples married in the Golden State while it was available from June to November. Proponents of the law have asked the state Supreme Court to nullify those marriages, while opponents have sought to have the law invalidated.

Many of Saturday's protesters were still reeling from that loss.

“I'm deeply offended by people trying to repeal our being married,” Barbara Keehn, who legally married her wife, Colleen Hines, in California during the “summer of love,” told the San Diego Union-Tribune. “It's a slap in the face.”

Protesters in Chicago marched in the downtown area and called on President-elect Barack Obama to repeal DOMA.

Obama repeatedly promised during the presidential campaign that he would work to repeal DOMA, but few gay activists believe with the economy in a tailspin that this will be a priority for the new administration.

Bob Barr recently said he favors repeal of the law. “It truly is time to get the federal government out of the marriage business,” Barr wrote in an editorial published by the Los Angeles Times.

Neither man, however, is advocating gay rights. They both say the law was not needed.

“DOMA was an unnecessary encroachment by the federal government in an area traditionally reserved for the state,” Obama told gay weekly Philadelphia Gay News publisher Mark Segal.

“If one truly believes in federalism and the primacy of state government over the federal, DOMA is simply incompatible with those notions,” Barr wrote.

The Human Rights Campaign, the nation's largest gay and lesbian rights advocate, lists repeal of federal DOMA as a top priority.