South Dakota has become the latest battlefield in the abortion wars. A Nov. 7 referendum will let voters approve or reject a new law aimed at banning virtually all abortions in the state. South Dakota legislators passed the law earlier this year in a direct challenge to the Supreme Court's landmark 1973 decision, Roe v. Wade, which legalized abortion during most of a woman's pregnancy. Abortion-rights advocates in South Dakota forced a referendum on the measure, which would allow abortions only if necessary to protect a woman's life. The balloting is the first popular vote on an abortion ban since Oregon voters rejected such a measure in 1990. Meanwhile, the Supreme Court is set to hear arguments on Nov. 8 in the Bush administration's defense of the federal law banning what opponents call “partial-birth abortions.” The high court struck down a state ban in 2000, but anti-abortion groups hope two new justices may change the outcome this time around.