The ban is on the South Dakota ballot as Referred Law Six. It's getting the most attention of the 11 issues on the ballot. The ban outlaws abortions except to save the life of a pregnant woman. The law makes it a felony for doctors to perform abortions.
Leslie Unruh is chairman of the group Vote Yes for Life. She supports the state's abortion ban and says abortions hurt women. She understands there are times when women experience an unplanned pregnancy.
"When you have an unplanned pregnancy you need support," she says. "You need people around you that are familiar with you and you need not strangers making those types of those decisions but people who care about you. And not let politics or fear of someone pressure from someone make the decision. We feel it's real important that women are informed and educated and given all the information at the time of crisis pregnancy."
The abortion measure has split the state's medical professionals.
Lornell Hansen is a family practice physician in Sioux Falls. He supports the ban saying abortion should no longer be used as a form of birth control. He believes in it so strongly that he mailed out copies of the law to every physician in the state. He says people need to read the law instead of listening to how others interpret it.
Hansen uses an example of a pregnant woman discovering she has uterine cancer and the doctor determines she needs a hysterectomy. He quotes the law to illustrate how it allows choices for a woman and her doctor.
"And here it goes: 'The physician shall make reasonable medical efforts under the circumstances to preserve both the life of the mother and the life of the unborn child in a manner consistent with conventional medical practice.' If it's conventional medical practice for her to have a hysterectomy - even if that takes the life of the baby - that's conventional medical practice, isn't it?"
Not everyone agrees the law is that reasonable. Jan Nicolay is a former state legislator and chairman of the Vote No campaign. She calls the law rigid.
"This is probably the most restrictive piece of legislation that I've seen passed and introduced," she says. "Today one of the things that makes this a very difficult issue for the people especially as we've worked across the state and talk with people across the state is that there are no exceptions for rape and incest victims."
The law allows a woman to take emergency birth control before she tests positive for pregnancy. Some argue rape survivors don't always come forward and that emergency contraceptives aren't widely available. However, South Dakota law also lets pharmacists refuse to dispense medicine on moral grounds.
While Tuesday's vote is a South Dakota issue, sponsors of the legislation made no secret they have a larger goal. They're out to challenge the U.S. Supreme Court Ruling that legalized abortion.
Bill Richardson chairs the political science department at the University of South Dakota. He says the prospect of having this be the test case was irresistible to some lawmakers.
"Clearly we intended to be the tip of the spear of a fight that would perhaps bring down Roe versus Wade after all of this time because of the changes that occurred on the Supreme Court," he says. "The is with the addition of the two new justices the perception was the balance had shifted sufficiently that Roe versus Wade might be successfully challenged."
But instead of filing a lawsuit, opponents the legislation gathered enough signatures to force a public referendum.
About a hundred opponents of the ban recently gathered in front of the federal courthouse in Sioux Falls. During the rally people come to a microphone and explain why they're voting no. There's a legislator, a business woman, a pastor.
"Hi! My name is Mandy and I'm pregnant," one woman says as she steps up to the mike. "I'm looking forward to raising my child in a very loving home. Fortunately in South Dakota I have the ability to make that decision. Referred Law Six is harmful to women. Especially pregnant women and I'm voting no on Referred Law Six."
There's no counter rally on this day but one man parks a truck across the street covered with pictures of aborted fetuses.
While most South Dakotans are firmly on one side or the other, Dr. Brooks Ranney sees all sides. He's practiced obstetrics and gynecology in Yankton since 1948. He's delivered more than 7,000 babies over the years. He doesn't support abortion, but he doesn't support banning it either.
He says there are cases when doctors need to abort a pregnancy. He talks about a 13-year-old whose body isn't mature enough to take a pregnancy to full term. He talks about a woman who discovers she has cancer and needs treatment.
"All scattered through the care of women there are little things that turn up on an individual basis and you can't make laws up in Pierre that apply to them," he says. "The law up in Pierre is too absolute."
The South Dakota section of the American College of Obstetrician and Gynecologists opposes the ban. In a written statement it says the ban is not based on science. It strips women of their legal rights and criminalizes essential aspects of women's health care.
Tuesday's vote is unlikely to resolve this issue. If voters approve the abortion ban opponents including Planned Parenthood will likely file a federal lawsuit on the day after the vote. That will prevent the law from going into effect. If the ban fails, supporters say they will try again and again to make abortions illegal not only in South Dakota but in the entire United States.