NEW YORK - In poll after poll, Americans say the economy is the paramount issue facing the nation, with hot-button social issues trailing far behind. Nonetheless, abortion will likely be in the election-year spotlight in a slew of states facing possible votes on sweeping abortion bans.

In at least 12 states - including crucial national battlegrounds such as Ohio and Virginia - anti-abortion activists are seeking to place "personhood" measures on the ballot this year. The measures vary in some details, but in general they define human life as beginning with fertilization and are intended to ban virtually all abortions, even in cases of rape and incest.

Supporters and opponents of personhood were seeking to galvanize their camps this weekend during a flurry of rallies, vigils and fundraising events marking today's 39th anniversary of the Supreme Court's landmark Roe v. Wade ruling. Personhood measures, if approved, would directly challenge that ruling, which established a woman's right to an abortion.

Thus far, the personhood movement is 0 for 3, losing referendums in Colorado in 2008 and 2010 and in Mississippi last November. But instead of retreating, the movement is trying again in Colorado and expanding to every other region except the Northeast on the premise that it can influence public opinion even if the measures fail.

"These are defeats only if we quit," said Keith Mason, president of Personhood USA. "If we continue on, they are building blocks for success."

Mason likened his movement to the campaign to legalize same-sex marriage, noting that gay-rights activists had persevered and made headway despite losing referendums in all 30 states where voters have weighed in on the issue.

For now, it's unclear how many of the personhood proposals will actually go before voters later this year. Authorities have given the green light to gather signatures for proposed ballot measures in Colorado, Ohio, Montana and California, while legislators in Kansas, Virginia, Oklahoma, Wisconsin, Alabama and Georgia have been working on bills that could lead to personhood referendums.

In Nevada and Arkansas, personhood campaigns also are in place, but have been slowed by disputes over the wording of proposed ballot measures. In Florida, anti-abortion activists are gearing up to seek a referendum in 2014.

In Colorado, the new personhood measure is considered likely to qualify for the ballot again this year because of the state's relatively low threshold for petition signatures. It's frustrating to the state's abortion-rights activists, who spent heavily to defeat the 2008 and 2010 measures by better than 2-to-1 margins.

"It's very clear that one of the goals of the personhood movement is to waste our resources," said Vicki Cowart, president of Planned Parenthood of the Rocky Mountains. "Every dollar we're spending on getting people out to vote is a dollar not spent for birth control or sex education or breast exams."

Criticism of the personhood movement also has come from some anti-abortion groups which worry the strategy could backfire if federal courts became involved and upheld Roe v. Wade.

In Nevada, a coalition of anti-abortion groups spoke out Jan. 12 against the state's personhood initiative, saying it will hinder their cause in the long run.

"Initiatives like these provide political and financial windfalls to abortion advocates and their candidates," said the coalition, which included Eagle Forum and Nevada Right to Life.

Some national anti-abortion groups have made clear that their preferred strategy is to push state by state for incremental legislative restrictions - such as requiring women to undergo sonograms before an abortion, restricting insurance coverage of the procedure, and imposing tough regulations on abortion clinics.

According to a tally by the abortion-rights group NARAL Pro-Choice America, 69 bills aimed at restricting access to abortion were enacted last year in 26 states - the second-highest total in 16 years of tracking such data.

Charmaine Yoest of Americans United for Life, one of the anti-abortion groups active in state legislatures, said she expected many more victories this year. But she declined to endorse - or criticize - the campaign for personhood measures.

"Different pro-life groups have different strategies," she said.

In Ohio, the personhood proposal shares the political stage with the so-called heartbeat bill, which would outlaw abortions at the first detectable fetal heartbeat, sometimes as early as six weeks into pregnancy.

The bill, stricter than any existing state abortion limit, passed the Ohio House last June and is pending in the Senate.

A Quinnipiac University poll released Thursday suggested that Ohio voters were evenly split, with 45 percent supporting the measure and 46 percent opposing it. Senate President Tom Niehaus has suspended hearings on the legislation and says debate will resume after the state's March 6 primary.

If the bill is enacted, supporters hope to provoke a legal challenge of Roe v. Wade, which upheld a woman's right to an abortion until the fetus is viable outside the womb, usually at 22 to 24 weeks.

Dr. Christopher Estes, an obstetrician-gynecologist and abortion provider in Miami, described the influx of restrictive laws in Florida and elsewhere as dismaying.

"All these things don't do anything to decrease women's need for abortion," he said. "It just hurts their care - particularly for the most vulnerable women."

Estes, who teaches at the University of Miami's medical school, said pressure from anti-abortion activists is unlikely to ease.

"They are equally ignorant and determined - it's a bad combination," he said. "They're on a very misguided moral crusade and I don't see it going away."

In the presidential campaign, abortion has been mostly a secondary issue thus far, though that could change in the fall.

While President Barack Obama supports abortion rights, the remaining Republican candidates depict themselves as staunchly anti-abortion. Three of them - Newt Gingrich, Rick Santorum and Ron Paul - have signed the Personhood USA pledge, which says abortions "are always wrong and should be prohibited."

Former Massachusetts Gov. Mitt Romney has not signed the pledge, nor did he join his rivals in an anti-abortion forum Wednesday night in South Carolina sponsored by Personhood USA. However, Romney, who once supported legalized abortion, now condemns it and says a future Supreme Court should overturn Roe v. Wade.

For most voters, abortion is not a front-burner issue. In a Gallup Poll earlier this month, 66 percent of respondents said the most important issue facing America related to the economy, while 1 percent cited abortion.

Even among voters in Iowa's Republican caucus - a relatively conservative bloc - only 13 percent said abortion was the key issue in choosing a candidate.