North Dakota voters today could make their state the first to provide constitutional rights to embryos, giving a long-sought win to "personhood" supporters trying to expand the scope of anti-abortion laws.

Except this time its closest backers aren't calling it a personhood measure. And it's not clear what a win would actually mean.

Measure 1 in North Dakota would amend the state constitution with one line. It would guarantee: “The inalienable right to life of every human being at any stage of development must be recognized and protected.”

The language is pretty vague, and the North Dakota group behind the ballot initiative says this isn't a personhood measure. But the national personhood group supporting efforts to bestow legal protections at conception says it is.

Opponents of the measure say it would outlaw abortion in the state, which last year approved a six-week abortion ban now being challenged in federal court. They also warn it could have far-reaching effects on end-of-life care, access to some birth control methods and in-vitro fertilization.

Among anti-abortion advocates, there is stark disagreement whether trying to advance personhood measures is the right strategy. Anti-abortion advocates opposing personhood efforts say they don't account for those who think there should be some exceptions allowing for abortion, and they don't consider the chances the strict measures would hold up when the Supreme Court has recognized a right to abortion in Roe v. Wade.

While the North Dakota group behind Measure 1 distances itself from the personhood label, the ballot initiative recently polled pretty well. Fifty percent supported the measure while 33 percent opposed it, according to an early October poll from the University of North Dakota.

The Guttmacher Institute, a reproductive rights policy and research groups, said the ballot language in North Dakota mirrors a personhood question rejected by Mississippi voters in 2011. And in the case of Mississippi, there wasn't any doubt that the ballot question was a strict measure that would have effectively outlawed abortion and some birth control methods, raising new constitutional challenges.

"The language is very similar in both of the measures," said Elizabeth Nash of Guttmacher. "They both would have amended the state constitution, they both would have granted personhood at fertilization."

In Mississippi, polling close to that election indicated the deep-red state would become the first to bestow constitutional rights to fertilized eggs. But on Election Day in 2011, the measure was soundly defeated by 58 percent of voters.

"This was a very extreme measure," Nash said. "There were no exceptions, where even in very conservative states where the political climate is very hostile to abortion, you tend to see support for some exceptions."

Efforts to approve personhood measures in Colorado have changed significantly since 2008, when voters were asked to amend the state's constitution to define personhood at the moment of conception. That measure failed, and so did another in 2010.

This year, voters in Colorado will consider Amendment 67, which would add "unborn human beings" under the state's criminal code and wrongful death act. Personhood proponents supporting the measure, which looks likely to fail, say it would provide legal protections to victims of fetal homicide. But opponents say the measure would have far-reaching effects, limiting access to birth control and abortion.

Republican Senate candidate Cory Gardner, expected to unseat Sen. Mark Udall (D-Colo.) today, earlier this year reversed his past support of personhood measuers. Gardner, who had previously co-sponsored federal personhood legislation, said he feared the tactic would outlaw some forms of contraception.

The ultimate impact of either the North Dakota or Colorado ballot initiatives, if approved, seems fairly uncertain — aside from the fact that they would open new fronts in abortion litigation.