IF NOTHING ELSE, South Dakota's new antiabortion law created a rough national consensus on a difficult issue: Abortion-rights groups see the law as the fourth sign of the apocalypse; opponents of abortion see it as a tactical blunder. Few people on either side of the abortion divide would be unhappy if the new law disappeared tomorrow.

And while it won't happen tomorrow, the South Dakota law will eventually disappear. Abortion-rights advocates may attempt to overturn the law by referendum--which would have only a small chance of success. But failing that, they will seek, and find, refuge in the courts. Whichever trial judge gets the case, he will find against Gov. Mike Rounds. The Court of Appeals for the Eighth Circuit will uphold the trial judge. If Rounds appeals, Justice Clarence Thomas, who oversees the Eighth Circuit, will likely recommend that the High Court decline to hear it.

For opponents of abortion, that's probably the best-case scenario. Should the rest of the court not defer to Thomas' recommendation and vote to take the case, the South Dakota law could become another judicial reaffirmation of Roe v. Wade, like the 1992 decision in Planned Parenthood v. Casey, when the court decided that government may not require that a husband be informed about an abortion.

As Ramesh Ponnuru, author of a forthcoming book on the politics of abortion, The Party of Death, notes: "What we should be fighting for right now is not 'winning' the abortion debate; we should be fighting for the right to have this

Yet while South Dakota's ban may be spectacularly ill-timed, it is a good example of what the future of abortion will look like.

At some point in the medium-term future, Roe will fall. It may be undermined incrementally or overturned outright, but as a legal matter, Roe is such a tortured decision that it cannot stand indefinitely.

After Roe is abandoned, Americans will be forced to find an electoral compromise on abortion. Remember, if Roe v. Wade is overturned, abortion does not disappear or suddenly become illegal--it simply reverts to the states, where elected officials can make, and change, abortion laws according to the will of the people.

In a post-Roe world, as many as 20 states, mostly in the South and Midwest, might wind up with laws of the South Dakota variety. Another 20 or so states would have moderate abortion laws. Some seven to 10 states would have liberal laws that essentially allowed abortion on demand.

According to the Guttmacher Institute, there are roughly 1.3 million abortions per year in the United States. (That's about 245 abortions for every 1,000 live births.) Where abortion is practiced most often, it is likely to stay legal. Nearly 60 percent of abortions happen in states that even the Center for Reproductive Rights acknowledges are most likely to protect abortion rights in a post-Roe world.

To get a sense of the concentration, consider that New York, New Jersey, California, and Florida--all of which would have abortion-friendly laws--accounted for 569,520 abortions in 2000.