Los Angeles ? Energized by a comeback win, conservative activists want to apply the same formula they used to outlaw same-sex marriage in California to prevent other states from recognizing gay unions and President-elect Barack Obama from expanding the rights of gays and lesbians.

Leaders of the successful Proposition 8 campaign say an unusual coalition of evangelical Christians, Mormons and Roman Catholics built a majority at the polls Tuesday by harnessing the organizational muscle of churches to a mainstream message about what school children might be taught about gay relationships if the ban failed.

Same-sex marriage bans also won in Arizona and Florida. But in putting together the California victory, the coalition overcame opposition from the state’s political establishment and assumptions about how voters in the famously tolerant state would respond to taking away the rights the state’s highest court granted this spring.

“Everyone told me it could not be done, people do not care about this enough, you will be overwhelmed and you will lose,” said Maggie Gallagher, executive director of the National Organization for Marriage, a New Jersey group that provided seed money early this year to qualify the measure for the ballot.

“This is an issue people care about when they understand what is at stake and we mount a vigorous and visible defense of marriage,” Gallagher said.

Same-sex couples are expected to start marrying next week in Connecticut, the third state after Massachusetts and California where courts have held it was unconstitutional to bar same-sex couples from marrying.

Unlike California, Connecticut does not have an initiative process that would allow voters to override the judicial decision there. So Gallagher said anti-gay marriage groups plan to focus next on New Jersey and New York, where the state legislatures are being lobbied to pass laws legalizing same-sex marriage.

The plan is to mobilize the same religious factions that joined forces in California to deter lawmakers from “taking on this divisive social issue while we are in the middle of a huge financial crisis,” Gallagher said.

Campaign operatives attribute their success to the churches, which served as voter registration centers, phone banks and volunteer recruitment hubs.

Religious institutions also gave Proposition 8’s sponsors an avenue to a range of ethnic voters, including many Democrats, said Mat Staver, who heads the Florida-based Christian legal group Liberty Counsel.

Catholic and evangelical Hispanics and African-American Baptists stood alongside conservative white evangelicals in arguing for traditional marriage. Exit polls showed 70 percent of blacks supported the ban, a far higher percentage than any other race.

Gay-right activists attribute their loss in California in large part to overconfidence among Proposition 8 opponents. Although polls showed the measure far behind in mid-September, the Yes-on-8 campaign was raising far more money than its opponents.

“There was a lot of complacency. People didn’t believe it could have been this close, so we had to scramble to raise money.” said Yvette Martinez, political director for Equality for All, the coalition of gay, civil rights and liberal religious groups formed to fight the initiative.