SAN FRANCISCO (AP) – When gay and lesbian couples started getting married in California last week, one set of voices was quiet among the choruses of “Here Come the Brides” – those of the conservative activists who put a same-sex marriage ban on the November ballot.

Instead of appearing in front of the television cameras that recorded joyful couples applying for marriage licenses, the sponsors of the California Marriage Protection Act remained on the sidelines and cautioned their supporters against disrupting weddings.

“We wish these same-sex couples well. Our beef is not with them, but with the judges who have the arrogance to rule that California’s marriage laws the voters approved are somehow akin to racial discrimination,” Brian Brown, executive director of the National Organization for Marriage-California, said in a statement.

The low-key tactics show that opponents of same-sex marriage are concentrating on politically moderate voters as they try to add California to the list of 26 other states with constitutional amendments outlawing gay nuptials.

At least one recent poll showed registered voters leaning against the ballot measure – though results have been mixed – and people involved in the campaign said the effort could be doomed if gay-marriage opponents come off as mean-spirited.

“This campaign represents the broad majority of Californians who support marriage, but are also very decent and tolerant people. Decent and tolerant people don’t show up to harass and intimidate anyone,” said Andrew Pugno, legal adviser to ProtectMarriage.com, a coalition of religious and social conservative groups that sponsored the initiative.

For their part, gay-rights activists urged same-sex couples and their supporters to afford the occasion the dignity it deserved. San Francisco Mayor Gavin Newsom, who officiated the wedding of two lesbian activists in their 80s, dissuaded couples, for instance, from scheduling group weddings or wearing elaborate costumes.

“Everybody is saying to their supporters on both sides, ‘Tamp it down, don’t be outrageous in your conduct because it will turn people off,’” said Bob Stern, president of the Los Angeles-based Center for Governmental Studies, an independent nonpartisan think tank. “No outrageous displays of affection and no outrageous displays of hatred, because everybody is appealing to the middle.”

As part of their strategy, gay-rights groups are attempting to characterize the amendment’s backers as extremists who are out of touch with attitudes in California. They point to the full-page advertisements Washington-based Family Research Council took out in the Orange County Register and the Sacramento Bee on Sunday, saying the start of legal same-sex marriage would lead to the term “father” being removed from birth certificates.

“If you look at what the other side has been talking about recently, they are not talking about lesbian and gay couples,” said Geoffrey Kors, executive director of Equality California, the state’s largest gay-rights group. “They want to raise all kind of other issues because the way they feel they can have success is through fear.

“But fear won’t work now because the public now sees lesbian and gay couples getting married, and there is nothing to be concerned about,” Kors said.

Pugno said it was too soon to say how the amendment’s backers would use images from the week of weddings in their campaign. While so far their message has focused on the actions of the Supreme Court majority that struck down the state’s one-man one-woman marriage laws, pictures of two brides and two grooms could be used to convince voters that the definition of marriage is in their hands.

“In many ways, the images are a daily reminder that this major social change did not come through the democratic process, but from a 4-to-3 vote of the Supreme Court, and that will keep it fresh in the voters’ minds,” he said.

Maggie Linden, a public relations executive who is working on the campaign to defeat the referendum, said the extensive media coverage of couples standing in front of clergy with their parents and children at their sides will help make the case for, not against, same-sex marriage.

“Californians fundamentally, time and time again, vote in a way that says we believe in equality and we don’t want people treated differently,” Linden said. “The images of yesterday and the day before are exactly those images – they are living and committed lesbian and gay couples who are exercising their fundamental rights like everyone else.”

The ballot initiative would amend the state constitution to “provide that only marriage between a man and a woman is valid or recognized in California.” Its language was taken directly from a gay marriage ban enacted by voters in 2000, one of two the state Supreme Court found unconstitutional and struck down on May 15.

Opponents and supporters of the November marriage amendment say they could together spend $30 million campaigning. If their predictions prove true, that would be more than the nearly $27 million that was spent combined in the 24 states where such measures have been put to voters since 2004, according to figures compiled by the National Organization on Money in State Politics.