If Gov. Mike Rounds of South Dakota really wanted to advance the pro-life cause, he would have vetoed the bill that the state Legislature sent him earlier this month.

The measure bans abortion in all cases except when the unborn baby’s life endangers the life of the mother. Granted, no true pro-lifer can disagree with the goal of the legislation, which seeks to protect vulnerable women and their unborn children. But its radical strategy, of banning abortion even in cases of rape and incest, will only end up hurting the right-to-life movement.

State Rep. Roger Hunt, R-Brandon, a sponsor of the bill, in a USA Today column on Feb. 28 made a compelling moral and legal case for the legislation.

He wrote, “Once human life can be medically determined, that unborn human life enjoys the same right to due process and equal protection of the law that a born human being does.” Agreed, but his political argument was weak.

He contended that many states, such as Ohio and Kentucky, have introduced similar measures. What he failed to note is that so far no states have passed them.

There’s a reason for that: South Dakota’s radical strategy is bad politics. Like some of the bold civil rights legislation in the 1950s, it is too far ahead of public opinion.

Imagine that Republicans called for invading Iran or that Democrats proposed banning all firearms except for hunting rifles. Each of those measures would be roughly as popular as the abortion standards endorsed by the South Dakota Legislature.

Americans simply don’t support prohibiting abortion in the hard cases. In January 2003, a poll taken by CNN, USA Today and Gallup asked 1,002 respondents if abortion should be legal “[w]hen the pregnancy is caused by rape and incest.” More than three quarters said abortion should be legal under those circumstances. Less than one fifth said it should be illegal.

Saddling pro-life candidates to support such unpopular standards will only hurt their chances of getting elected or re-elected. Consider the prospects of pro-life candidates in states with a Democratic majority, for example.

A right-to-life senator like Gordon Smith of Oregon, who’s up for re-election in 2008, would face a tougher time winning if he has to support abortion in the hard cases. As Dan McConchie, spokesman for Americans United for Life, told me, “Republicans’ ability to keep control of the Senate is already tough, with the Jack Abramoff scandal and all. But forcing them to support this [the South Dakota standards] makes it even tougher.” Indeed, if Republicans in the Senate lose six seats in November, Democrats will take over.

What’s more, the South Dakota bill needlessly energizes the other side. Already, pro-abortion groups are literally capitalizing on the proposal. “URGENT. South Dakota poised to ban abortion. Help us fight back today. Click here,” reads an ad in the upper-right hand corner of the website for NARAL Pro-Choice America. Clicking on the site yields a page in which a person can choose a donation in the amount of $35 to $250 or even more.

Nor is the South Dakota legislation likely to succeed in the courts. District courts are almost certain of knocking it down. After all, most of them struck down the ban on partial-birth abortion, a measure that enjoys wide popular support. And the Supreme Court is unlikely to take up the case. At best, only four of the nine justices are likely to overturn Roe v. Wade and Doe v. Bolton, the twin cases in 1973 that legalized abortion nationwide. For example, Justice Anthony Kennedy in Casey v. Planned Parenthood in 1992 voted to uphold Roe and Doe.

Losing at the ballot box and in the courts is simply not what the right-to-life movement needs.

The reason the movement started winning was that after Casey, pro-life leaders made a conscious choice. They ditched their radical strategy, such as trying to pass a human-life amendment. In its place they adopted an incremental strategy, one that limits abortion but does not ban it. Opponents call this “chipping away” at abortion rights, but whatever the name, the tactics worked.

Consider all of the subsequent pro-life gains. State legislatures have enacted more than 500 new abortion curbs. The Supreme Court is poised to approve a ban on partial-birth abortion. Sen. Hillary Clinton, D-N.Y., acknowledges that abortion is “a painful, even tragic choice for many women.” Planned Parenthood, recognizing the spiritual trauma of abortion, now employs religious chaplains. And on March 3, the Center for American Progress, a liberal think tank, will hold an unprecedented summit among abortion-rights leaders and supporters.

Those advances were made not by a radical strategy but by an incremental one. And more incremental steps need to be taken. Congress and the states should fund sonogram machines, pass laws mandating parental involvement, and prohibit abortion for all health and economic reasons.

Those are battles that pro-lifers can win. But if states like South Dakota start banning abortion in the hard cases, right-to-lifers will be forced to fight battles they can only lose.

Next Week: Defending South Dakota.

Mark Stricherz, a writer

in Washington, D.C., keeps

a weblog at InFrontofYourNose.com.