(Rogelio V. Solis/AP)

“Things can definitely go either way tomorrow,” said Public Policy Polling director Tom Jensen. “The stakes here are huge. This is really the most interesting thing on the ballot tomorrow anywhere in the country.”

The Mississippi ballot has incredibly important legal implications: no state has ever given an embryo constitutional rights and, legally, it’s not quite clear what happens when you do. There is a lot of speculation that it could outlaw infertility treatments and birth control, while almost certainly banning abortion. If passed, the Mississippi law would near certainly bait a legal challenge that could wind its way up to the Supreme Court.

Only one other state, Colorado, has ever voted on a personhood amendment. It actually did so twice, in 2008 and 2010, and in the run-up to both votes, polling numbers never even got within single digits. Each time, the ballot headed into voting day near certain to fail. But in Mississippi that doesn’t look to be the case.

Politically, the Mississippi amendment will say a lot about the future of the anti-abortion movement. For years now, the movement has struggled over how best to push back against abortion rights. The mainstream movement has moved pragmatically and methodically, passing dozens of laws like waiting periods prior to abortions or mandatory parental notification.

That incremental approach has frustrated the more aggressive activists who’ve embraced the personhood movement, which takes e a more ideological approach to the issue: abortion is immoral, and leaves no space for small changes around the edges. “They’ve just taken an incremental approach,” Les Riley, the founder of Personhood Mississippi, recently told my colleague. “We’re just going to the heart of the matter, which is: Is this a person or not? God says it is, and science has confirmed it.”

Activists like Riley have generally struggled to gain footing within the anti-abortion movement. While Colorado has voted on the issue, a half-dozen efforts to force votes on personhood amendments have failed to gain enough signatures for a spot on a state ballot. If the Mississippi ballot passes — and this poll suggests it very well could — it will be an unprecedented success for the more aggressive wing of the anti-abortion movement.

As to what happens tomorrow, Jensen at Public Policy Polling says much will hinge on turnout. African-American voters, who oppose the amendment by wide margins, tend to have historically low voter turn out in the state. A lack of a strong Democratic contender for governor — the race is widely expected to go Republican Phil Bryant — could challenge personhood opponents in getting voters to the polls.

“It’s a concern that folks trying to defeat the amendment need to keep in mind,” says Jensen. “Really, what they have to hope for is people come out to vote on the amendment itself, not the governor’s race.”