SALEM - With little fanfare, a coalition of social conservative and church groups began rounding up petition signatures last week hoping to derail two gay rights measures passed by the Legislature.

Their aim is to give voters in November 2008 a chance to repeal a domestic partnership law to give gays and lesbians most of the benefits of marriage under state law along with another new law banning discrimination based on sexual orientation.

The social conservatives see it as a resumption of a battle that began in the November 2004 election, when Oregon voters adopted a constitutional ban on gay marriage.

Others, however, say the issues are different this time around, and that public attitudes about gays and lesbians are shifting.

They point to what happened last November in Arizona. Voters in that politically conservative state rejected a constitutional amendment defining marriage as the union of one man and one woman, making Arizona the first state to turn down a gay marriage ban at the ballot box.

Nathaniel Persily, a professor of law and political science at the University of Pennsylvania, said the issue became “highly politicized” in 2004 - a presidential election year - when voters in Oregon and 10 other states adopted bans on same-sex marriage.

Since then the furor over the issue has subsided, Persily said.

“Most people are still uncomfortable attaching the word ‘marriage' to same-sex relationships,” he said. “But our research shows most Americans are willing to have some legal recognition for same-sex relationships that falls short of marriage.”

Opponents of Oregon's new laws say those measures, particularly the domestic partnerships law, go against what Oregon voters wanted when they approved the 2004 ban on gay marriage.

“It's just marriage by another name,” said state Rep. Linda Flores, a Clackamas Republican who is backing the effort to repeal the two laws. “The Legislature is trying to overturn the will of the voters. That's the frustration that I'm hearing from a lot of people.”

All sides predict the gay rights opponents will be able to gather the 55,179 signatures needed to refer each of the measures to the November 2008 ballot. It's also expected to spark one of the most expensive - and some say nasty - campaigns the state has seen in years.

There's a lot riding on the election for Tim Smith and Kent Kullby, a same-sex couple from Eugene who plan to register as domestic partners under the new law.

“We want what other Americans already have - full legal equality. Nothing more, and nothing less,” Smith, who owns a small business, said in a recent interview.

A spokeswoman for the state's leading gay rights group said public opinion polls done for the group indicate a majority of Oregonians support giving same-sex couple rights and protections similar to marriage - but not full-on marriage at this point.

Still, Basic Rights Oregon spokeswoman Melissa Chernaik said gay rights groups here and nationally are prepared for an expensive election campaign to defend the political gains they achieved in the Oregon Legislature this year.

“It's been 34 years in the making,” Chernaik said, referring to gay rights bills that were first introduced in the Legislature in 1973. “Folks are not going to be willing to let those laws die without a huge fight.”

The vote is likely to bring out lots of voters on both sides for what's already expected to be a high-turnout presidential election next year.

Kevin Mannix, a former state lawmaker and Republican gubernatorial contender, said he's convinced the 2004 gay marriage amendment helped drive up Republican voter participation in that year's presidential election. Nearly 90 percent of registered Republicans voted that year, compared with 85 percent in 2000.

“There were a number of our voters who were particularly motivated by that issue,” Mannix said.

Independent pollster Tim Hibbitts said he thinks the domestic partners law, as well as the anti-discrimination measure, might be upheld by Oregon voters if gay rights backers can persuade people those measures are not an end-run around the 2004 gay marriage ban.

“Gay rights backers are on some reasonable ground in hoping that voters will differentiate between gay marriage and domestic partnerships,” Hibbitts said.

Either way, he said Oregon could be in for a high profile, multimillion-dollar campaign.

“If these get on the ballot, you can expect it to be very emotional and very nasty,” Hibbitts said.