MOUNT LAUREL, N.J. (AP) – Opponents of same-sex marriage say their easiest political work is done: Most states have passed laws or constitutional amendments banning recognition of same-sex unions.

Now they say their task is getting more difficult: Seeking to ban same-sex marriage in some of the nation’s most gay-friendly states.

A Princeton-based group, the National Organization for Marriage, is targeting its message against same-sex marriage in California, one of two states that currently allow it, and a handful of other states that might consider it in the next few years.

The organization, known as NOM, is leading the support of a constitutional amendment in California that would put an end to the same-sex marriages that have been allowed there since last month.

While most of its efforts between now and the November vote will likely be in California, the group also is gearing up for battles over same-sex marriage in Florida, New Jersey, New York, Connecticut and Rhode Island.

NOM is targeting Democratic-voting states on the coasts because those are the places its opponents think they have the best chance, according to Maggie Gallagher, a syndicated columnist who founded the organization a year ago with Robert George, a Princeton University professor.

“They’re not choosing to push same-sex marriage through legislation in Alabama,” Gallagher said.

A decade ago, the idea of same-sex marriage seemed like a pipe dream to its supporters and nothing to worry about to its opponents.

But since the high court in Vermont ruled in 2000 that same-sex couples should be treated the same as opposite-sex couples, expanding recognition of same-sex couples has become an attainable goal for its supporters. And the fight against same-sex marriage has become a priority for social conservatives.

Twenty-six states have adopted constitutional amendments to bar same-sex marriage – nearly all of them after the Vermont court’s decision.

Since then, the top state courts in Massachusetts and California have legalized same-sex marriage and same-sex couples in eight other states – including New Jersey – and the District of Columbia have gotten some legal protections.

Most of the gains for same-sex couples have come through the courts, but the key debates are shifting from the courtroom to voting booths and state legislatures.

In California, Arizona and Florida, voters are being asked in November whether they want to ban same-sex marriage. In New Jersey and New York, legislatures are expected to consider laws to allow same-sex marriage in the next few years.

Evan Wolfson, founder of the national gay rights group Freedom to Marry, said groups like NOM are fighting an uphill battle as people see how same-sex marriage works in Massachusetts and California.

“It’s become clear to most Americans that there is no real good argument against allowing gays to marry,” Wolfson said. “They can see with their own eyes that the gays didn’t use up all the marriage licenses.”

Len Deo, the president of the Family Policy Council of New Jersey, one of the state’s leading socially conservative political organizations, said his group is usually overmatched by liberal interests in the Statehouse and can use the help of national organizations.

That’s where Gallagher’s group comes in – with the aim of helping conservative state organizations fend off same-sex marriage, particularly in states where gay rights groups get help from national organizations such as the Human Rights Campaign.

“It’s a strategic and tactical mismatch to have their best national people going up against our best state people,” Gallagher said.

NOM, a taxable political advocacy group that can raise money without contribution limits, has quickly built up some fund-raising muscle.

It started a California chapter in January. By March, the group had raised just more than $775,000, according to campaign finance filings. Only the California umbrella group ProtectMarriage.com has raised more for the cause.

While NOM’s biggest chunk in California – $250,000 – came from the Knights of Columbus, the group has also raised smaller amounts from individuals. The group says it has now raised more than $1 million in California and more than $2 million overall.

Wolfson, of the Freedom To Marry organization, says that while NOM’s name may be new, the concept is not. He said much of the money seems to come from the same donors who give consistently to socially conservative political efforts.

In California, the organization used some of its money to hire people to collect signatures to get the marriage amendment on the ballot. Now that the question is on the ballot, the emphasis is on campaigning for it.

Gallagher said the group, which has aired some radio advertisements in New Jersey and New York, is also producing television and radio advertisements that can be adapted for use in states across the country.