The ban made one exception: cases where a mother's life is threatened. But two other exceptions, for rape and incest, were intentionally left out. Those exceptions are widely popular, and it would have been easy for lawmakers to include them in the bill and tell pro-lifers that it would still outlaw the vast majority of abortions. (Rape and incest cases account for only 2 percent or so.)

But they didn't do that. They acted on the principle that the law's first duty is to protect innocent life, and nothing can justify taking such a life except the need to preserve another life. They intentionally risked the ire of their home state voters and exposed themselves to vilification by abortion-rights supporters (including the powerful Planned Parenthood) nationwide.

Why? The cynical mind searches for a cynical explanation. I've followed politics long enough that I'm in the cynical category, and I imagine there were some people in the picture who acted for self-serving motives. But all in all, it's hard to see how the evidence points in that direction. The answer to the "why" question seems to be, believe it or not, because a lot of people were convinced it was the right thing to do. As Gov. Mike Rounds put it:

In the history of the world, the true test of a civilization is how well people treat the most vulnerable and most helpless in their society. The sponsors and supporters of this bill believe that abortion is wrong because unborn children are the most vulnerable and most helpless persons in our society. I agree with them.

It's as simple as that. Regrettably, Rounds hasn't talked a lot about the issue since signing the bill. But he did sign it, and the legislators did pass it. That took real guts, any way you slice it.

The South Dakotans' stand gets even more impressive when you consider what they're up against. One reason this bill was passed now was because the U.S. Supreme Court (which will doubtless rule on the law in the end) has two new judges, John Roberts and Samuel Alito, both of whom might vote to overturn the Court's initial abortion-rights rulings, Roe v. Wade and Doe v. Bolton. But even if they do, the Court is still one vote short of taking that action, by any count. Unless another anti-Roe member joins the Court during the few years it'll take for this case to wind through the court system, the South Dakotans are going to lose, and they had to know it.

You could question, I suppose, their political wisdom. After all, this is only going to make things harder on the next Republican Court nominee, if there is one in the next few years. It'll rev up abortion-rights forces who'll argue that the most central "right" of the modern age is truly one vote away from being lost. It'll make Roberts and Alito (who in their confirmation hearings declined to comment on cases that could come before the Court) show where they stand — and if they vote against Roe, it'll increase pressure on the next nominee to definitively pledge allegiance to affirming abortion. And it'll do the same to politicians, who'll face more demands than ever to show where they stand. That'll especially go for senators: Each one could turn out to be the swing vote.

Yet the South Dakotans had a bigger vision than this. There's reason to believe that a lot of them not only felt compelled to take a stand, but also understood how vital it is to make everyone else take a stand too.

"We decided it was time to have this discussion in South Dakota," said South Dakota's Senate president, Lee Schoenbeck, a major sponsor of the law. "We understood it would end up eventually being challenged in the courts and would hopefully lead, through the course of those appeals, to a national decision."

That's good to hear, senator. For decades now, numerous politicians have told pro-lifers: "Hey, we're on your side, and we'd love to help you out. But darn it all, the Supreme Court has spoken, and we all have no choice but to abide by their ruling." Their legal argument is dead wrong: The Constitution does not mean whatever the Court says it means, and legislators are not bound to follow rulings the Court has no authority to make. But since few Americans know their Constitution, politicians can get away with this. They can pass a few popular limits on abortion (parental notice, waiting periods, etc.) without touching the core "right"; they can appease pro-lifers without ticking off many other people.

The message from South Dakota is: No longer. Abortion is a hugely important moral issue, the lawmakers insist, central to the moral foundation of our society. So there'll be no more ducking and dodging it, no more deferring it to some distant future day when we have a "culture of life" that makes it safe for politicians to touch the fundamental issue without getting burned. We need to deal with it, they say — starting now.

Some will say they're being wildly impractical. I think they're being refreshingly realistic. If we're ever going to get a culture of life, it'll never come from stealthy advances into the centers of governmental power: It will only come from public, persistent fighting for principle. Nor will it come from people who are afraid to proclaim the sanctity of human life as a binding truth (not a mere "personal" belief) recognized by the law. It will only come from people who aren't afraid to risk taking heat and losing elections for the sake of what's right.

Which brings us back to courage — and no wonder, because there's no substitute for it. We can debate tactics, but there's no disputing this: "Courage," as C.S. Lewis noted, "is not simply one of the virtues, but the form of every virtue at the testing point."

South Dakota's lawmakers have passed that test. Let's hope, and pray, they've got plenty of company.