That makes Buehner furious. If you treated that woman's cancer without terminating the pregnancy first, he said, "you'd have a dead fetus in an irradiated pelvis in an immune system compromised by chemotherapy. So when she starts to hemorrhage from her miscarriage, emptying her uterus will be fraught with peril."

Anti-abortion forces say the other side is deliberately focusing on a handful of horrible cases rather than on the vast majority of abortions, which they claim are done for "convenience" or "birth control."

"We need to protect the lives of millions of unborn children," said state Rep. Roger Hunt, a Republican who sponsored the ban.

Andrew Johnson, a 22-year-old senior at the South Dakota School of Mines and Technology in Rapid City, said he planned to vote "Yes" on the abortion ban "for religious and moral reasons."

"Also," he said, "some supporters are women who have had abortions, and it really affected them mentally and physically." Johnson said adoption was a better alternative, "and then that child will have a chance to live."

The issue has mobilized South Dakotans who were never active before, from teenagers to octogenarians.

"This legislation has made people awaken from their complacency," said Jessica Nathanson, an assistant professor of English and gender studies at Augustana.

Last March, when Gov. Mike Rounds signed the abortion ban, "it really got me fired up," said Augustana student Judie Marshall. Marshall, 19, is working with Andert to register voters and shuttle them to the Minnehaha County Courthouse, where they can vote early with absentee ballots.

Dr. Anne Fisher, 50, an emergency physician, volunteers at the Rapid City headquarters of the South Dakota Campaign for Healthy Families, the coalition fighting to repeal the ban, known officially as Referred Law 6.

"I was never involved in a political campaign before," said Fisher, who said she's never performed an abortion and wouldn't have one herself. "But this is just incredibly important. The law is so unfair. It's worth taking a stand publicly."

The anti-abortion side is equally passionate. Church groups have been busing teenagers to the state capitol to lobby politicians. One Baptist congregation in Rapid City has had a voter-registration table at its Sunday services. And VoteYesForLife.com, the organization fighting to retain the ban, says it has "thousands" of volunteers planting lawn signs, manning phone banks and holding house parties.