ANNIVERSARIES don't get much more controversial than this. On January 22nd, America will mark the thirtieth anniversary of the Supreme Court decision that declared abortion a constitutional right. Anti-abortionists will march in Washington in their thousands, carrying gruesome photographs. Supporters of abortion rights will retort that Roe v Wade, the decision in question, was one of the great milestones in the long march for women's rights—a heroic decision that has saved thousands of women from death by coat-hanger or back-street butchery. The two sides will end the day even more polarised than ever.

Since 1973, about 75 countries have liberalised their abortion laws (the most recent being Switzerland and Nepal last year). In most countries, that was enough to settle the debate. Not in America.

The Supreme Court's ruling immediately created a furious backlash. State legislatures passed laws restricting the rights of minors to obtain abortions, usually by requiring the consent of one or both parents. In 1976 Henry Hyde, an Illinois congressman, sponsored legislation eliminating Medicaid funding for abortions except in extreme cases (such as rape, incest or where a woman's life was endangered by her pregnancy). Some extremists took to blowing up clinics and shooting abortion doctors (who, in turn, took to coming to work wearing bullet-proof vests).

Why does abortion remain so much more controversial in America than in the other countries that have legalised it? The fundamental reason is the way the Americans went about legalisation. European countries did so through legislation and, occasionally, referenda. This allowed abortion opponents to vent their objections and legislators to adjust the rules to local tastes. Above all, it gave legalisation the legitimacy of majority support.

Most European countries provide abortion free. But they have also hedged the practice with all sorts of qualifications. They justify abortion on the basis of health rather than rights. Many European countries impose a 12-week limit (America, by contrast, allows abortion up to about 24 weeks and beyond, and many abortion-rights advocates seem to oppose any restrictions.) Frances Kissling, head of Catholics for a Free Choice, also points out that the Europeans have been careful to preserve a patina of disapproval. Even in England, the country with the most liberal abortion laws in Europe, women have to get permission from two doctors.

America went down the alternative route of declaring abortion a constitutional right. (The only other country that has done anything comparable is South Africa.) A seven-to-two majority of justices struck down state abortion laws on the grounds that reproductive rights are included in a fundamental right to privacy which—rather like freedom of speech and freedom of religion—is guaranteed by the constitution.

A second reason is the continued importance of religion in American life. The Pew Global Attitudes Project recently revealed that six in ten (59%) of Americans say that religion plays a “very important” role in their lives. This is roughly twice the percentage of self-avowed religious people in Canada (30%) and an even higher proportion when compared with Japan and Europe. To find comparable numbers, you need to look at developing countries.

When Americans say “very important”, they mean it. America, in Robert Fogel's phrase, is in the middle of a “fourth great awakening” to religion. Churches that insist on passionate commitment to Christ are growing at the expense of more moderate congregations. Religious organisations also provide many of the social services that the state provides in Europe.

The third reason why abortion is so controversial is the American fondness for arguing about fundamentals. Europeans routinely turn moral issues into technical ones—and then hand them over to technocratic elites. America is a country of fundamentalists, thanks to its constitutional tradition, its legal culture and perhaps its Puritan heritage. For Americans, abortion can never be just about health. It has to be a clash of absolutes: the right to choose versus the right to life. Add to that the openness of the American political system, which makes it impossible to hand controversial questions over to technocratic elites, and you have the making of an endless argument about fundamentals.

The party divide

Roe v Wade did as much as anything to make American politics what it is today. Up until the 1960s, politics was defined by a combination of economic class and the legacy of the civil war. The Republicans, like Europe's conservative parties, were rooted in the business and professional elites; the Democrats were rooted in the trade unions, the urban political machines and ethnic minorities, mostly Irish and Italian. White southerners of all classes also voted Democratic (a legacy of Republican opposition to slavery). Those most opposed to abortion—Catholics and southerners—were almost all Democrats.

But from the mid-1960s onwards values started to trump class. Abortion was not the first issue that redefined politics: that honour goes to civil rights. But it was certainly one of the most powerful. Roe helped to drive millions of northern Catholics and southern evangelicals into the Republican Party. (Republicans dubbed George McGovern the triple-A candidate: amnesty, acid and abortion.) It also persuaded Catholics and evangelicals to put aside their long-standing enmity in order to form a common front. The term “moral majority” was first used by Paul Weyrich, an arch-traditional Catholic, in a presentation to Jerry Falwell, a leading evangelical.

There are still pro-choice Republicans (like Colin Powell) and anti-abortion Democrats. But they are swimming against the tide. Some 84% of state Democratic platforms support abortion (the rest have no position), while 88% of state Republican platforms oppose it (none support it). The Republican Party threw away its chance of wresting the governorship of California from the hugely unpopular Gray Davis when it chose an anti-abortion candidate, Bill Simon, over Richard Riordan, the popular former mayor of Los Angeles.

The abortion debate is also responsible for one of the most obvious confusions in the political debate. Republicans usually oppose government regulation in the name of free choice. Grover Norquist, the head of Americans for Tax Reform, even goes so far as to call the Republicans the “leave-us-alone coalition”. But on the most sensitive subject of all—reproductive rights—conservatives are now on the side of government control. The Democrats are no more coherent: a party that will do anything to protect a woman's right to choose an abortion will not support her right to choose a public school for her child.

Roe has left the American legal system hopelessly politicised. The Democrats destroyed Robert Bork's chances of sitting on the Supreme Court in part because of his presumed views on abortion. Abortion politics are even poisoning the appointment of lower-level judges (despite the fact that they have almost no discretion over abortion), creating ever more vacancies on the bench and denying many eminent lawyers the promotion they deserve. The Senate confirmed 95% of Ronald Reagan's circuit-court nominees in his first two years, and 86% of Bill Clinton's; so far, it has confirmed 53% of Mr Bush's.

The abortion debate has more practical implications, too. The number of doctors willing to practise this branch of medicine is declining, in part because of fear of violence. It took years for RU486, the “abortion pill” that is common in Europe, to make it to the United States. Mr. Bush, sensitive to pressure from the Christian right, severely restricted embryonic stem-cell research in the United States, a decision that some scientists think could cost America its lead in a vital area of research.

A future of stalemate

Where is abortion politics going? The abortion-rights camp believes that their position is as perilous as it has been for 30 years. This is the first time since 1973 that the president, the leader of the Senate and the leader of the House have all been opposed to abortion.

Many anti-abortionists are also quietly convinced that they are winning the battle for people's minds. They have highlighted rare practices like “partial-birth abortion” that most people find repugnant: the name in itself is a propaganda coup. They are busy building what they call a “coalition of the vulnerable”, arguing that, if people are prepared to dispose of inconvenient fetuses, they will start disposing of inconvenient old people, sick people and poor people. According to a Gallup poll, the proportion of the public who believe that abortion should be legal in all cases has gone down from 34% in 1992 to 24%.

Anti-abortionists have also relentlessly whittled away at abortion rights. Every year new legislation restricting abortion is introduced in statehouses across the country. A long queue of anti-abortion bills is awaiting consideration in Congress. The Child Custody Protection Act makes it a crime for anybody other than the parent to transport a minor across state lines in order to have an abortion. The Unborn Victims of Violence Act (which is similar to bills introduced in many states) creates a new offence: killing or injuring a fetus during the commission of a federal crime. The Bush administration has made fetuses eligible for the State Children's Health Insurance Programme, and directed the Advisory Commission on Human Research Protection to consider embryos as “human research subjects” on a par with children.

There are several problems with this argument. The biggest is that most Americans want to preserve abortion rights. They don't celebrate abortion. They recoil at partial-birth abortion. But they want no return to the back streets. Their attitude was perfectly captured by Mr. Clinton when he said that he wanted abortion to remain “safe, legal and rare”. Support for the status quo is strongly reinforced by the fact that Roe v Wade is now 30 years old. Most women of child-bearing age have grown up with Roe as the law of the land.

Scientific advances also cut both ways. The morning-after pill can be used to induce abortion almost immediately after conception. Stem cells offer the potential of curing Parkinson's disease. The anti-abortion movement's insistence that a tiny clump of cells constitutes life just as much as a 24-week-old fetus makes it look both extreme and uncaring. Several leading Republicans, including Utah's Orrin Hatch, have broken with the anti-abortion movement over embryonic stem-cell research.

Abortion is now better regulated than ever before. Many of the restrictions on abortion rights imposed by anti-abortionists have had the paradoxical effect of making the practice more acceptable. More than half of all abortions are now performed in the first eight weeks of pregnancy, up from under 40% in 1973, and 89% in the first 12 weeks. A report just released by the Alan Guttmacher Institute also shows abortions at an all-time low of 21.3 per 1,000 women aged 15-44, compared with the 1980-81 peak of 29.3.

Lastly, Republican presidents are terrified of pushing the abortion issue too far. They are happy to throw a few bones to the religious right (which is why development aid is such a convenient target). But they realise that challenging the central principle of Roe would doom them with moderate voters—particularly women. In his confirmation hearings, John Ashcroft, the attorney-general, was following White House instructions when he described Roe as “the settled law of the land”. “The Supreme Court's decisions on this have been multiple, they have been recent, and they have been emphatic,” he said.

Emphatic indeed. The court reaffirmed Roe's central principle—that states cannot ban abortions—as recently as 1992, by a five-to-four majority, in the case of Planned Parenthood v Casey. In doing so, it cited the need for stability in the law. In 2000, the same majority struck down Nebraska's ban on partial-birth abortion. And even if the court should revisit the case, there is little chance that it will reverse itself and make abortion illegal. The most that anti-abortion justices such as Antonin Scalia argue for is taking the decision away from the Supreme Court and handing it back to the legislatures. The betting is that almost all legislatures would uphold the right to abortion.

Is there any chance that the opposite will happen—and that abortion will become as uncontroversial in the United States as it is in Europe? Not really. The last 30 years of abortion politics have seen the creation of two pressure groups with a vested interest in keeping the debate as fierce as possible. Ken Connor of the FRC is thoroughly connected to the Republican establishment. And the best way for Kate Michelman, the head of NARAL Pro-Choice America, to shake the liberal money trees is to insist that Roe is on the verge of being overturned. There is no chance of America becoming “European” in its attitude to abortion.

Roe v Wade may have liberated many women; yet it has also trapped America in an irresolvable clash of absolutes. The one safe prediction is that the issue will continue to shape the war between left and right for years to come—and that the fortieth anniversary of Roe v Wade will be just as acrimonious as the thirtieth.