Barack Obama is the most extreme pro-abortion candidate ever to seek the office of President of the United States. He is the most extreme pro-abortion member of the United States Senate. Indeed, he is the most extreme pro-abortion legislator ever to serve in either house of the United States Congress.

Yet there are Catholics and Evangelicals — even self-identified pro-life Catholics and Evangelicals — who aggressively promote Obama's candidacy and even declare him the preferred candidate from the pro-life point of view.

What is going on here?

I have examined the arguments advanced by Obama's self-identified pro-life supporters, and they are spectacularly weak. It is nearly unfathomable to me that those advancing them can honestly believe what they are saying. But before proving my claims about Obama's abortion extremism, let me explain why I have described Obama as 'pro-abortion' rather than 'pro-choice.'

According to the standard argument for the distinction between these labels, nobody is pro-abortion. Everybody would prefer a world without abortions. After all, what woman would deliberately get pregnant just to have an abortion? But given the world as it is, sometimes women find themselves with unplanned pregnancies at times in their lives when having a baby would present significant problems for them. So even if abortion is not medically required, it should be permitted, made as widely available as possible and, when necessary, paid for with taxpayers' money.

The defect in this argument can easily be brought into focus if we shift to the moral question that vexed an earlier generation of Americans: slavery. Many people at the time of the American founding would have preferred a world without slavery but nonetheless opposed abolition. Such people — Thomas Jefferson was one — reasoned that, given the world as it was, with slavery woven into the fabric of society just as it had often been throughout history, the economic consequences of abolition for society as a whole and for owners of plantations and other businesses that relied on slave labor would be dire. Many people who argued in this way were not monsters but honest and sincere, albeit profoundly mistaken. Some (though not Jefferson) showed their personal opposition to slavery by declining to own slaves themselves or freeing slaves whom they had purchased or inherited. They certainly didn't think anyone should be forced to own slaves. Still, they maintained that slavery should remain a legally permitted option and be given constitutional protection.

Would we describe such people, not as pro-slavery, but as 'pro-choice'? Of course we would not. It wouldn't matter to us that they were 'personally opposed' to slavery, or that they wished that slavery were 'unnecessary,' or that they wouldn't dream of forcing anyone to own slaves. We would hoot at the faux sophistication of a placard that said 'Against slavery? Don't own one.' We would observe that the fundamental divide is between people who believe that law and public power should permit slavery, and those who think that owning slaves is an unjust choice that should be prohibited.

Just for the sake of argument, though, let us assume that there could be a morally meaningful distinction between being 'pro-abortion' and being 'pro-choice.' Who would qualify for the latter description? Barack Obama certainly would not. For, unlike his running mate Joe Biden, Obama does not think that abortion is a purely private choice that public authority should refrain from getting involved in. Now, Senator Biden is hardly pro-life. He believes that the killing of the unborn should be legally permitted and relatively unencumbered. But unlike Obama, at least Biden has sometimes opposed using taxpayer dollars to fund abortion, thereby leaving Americans free to choose not to implicate themselves in it. If we stretch things to create a meaningful category called 'pro-choice,' then Biden might be a plausible candidate for the label; at least on occasions when he respects your choice or mine not to facilitate deliberate feticide.

The same cannot be said for Barack Obama. For starters, he supports legislation that would repeal the Hyde Amendment, which protects pro-life citizens from having to pay for abortions that are not necessary to save the life of the mother and are not the result of rape or incest. The abortion industry laments that this longstanding federal law, according to the pro-abortion group NARAL, "forces about half the women who would otherwise have abortions to carry unintended pregnancies to term and bear children against their wishes instead." In other words, a whole lot of people who are alive today would have been exterminated in utero were it not for the Hyde Amendment. Obama has promised to reverse the situation so that abortions that the industry complains are not happening (because the federal government is not subsidizing them) would happen. That is why people who profit from abortion love Obama even more than they do his running mate.

But this barely scratches the surface of Obama's extremism. He has promised that 'the first thing I'd do as President is sign the Freedom of Choice Act' (known as FOCA). This proposed legislation would create a federally guaranteed "fundamental right" to abortion through all nine months of pregnancy, including, as Cardinal Justin Rigali of Philadelphia has noted in a statement condemning the proposed Act, 'a right to abort a fully developed child in the final weeks for undefined 'health' reasons.' In essence, FOCA would abolish virtually every existing state and federal limitation on abortion, including parental consent and notification laws for minors, state and federal funding restrictions on abortion, and conscience protections for pro-life citizens working in the health-care industry-protections against being forced to participate in the practice of abortion or else lose their jobs. The pro-abortion National Organization for Women has proclaimed with approval that FOCA would "sweep away hundreds of anti-abortion laws [and] policies."

It gets worse. Obama, unlike even many 'pro-choice' legislators, opposed the ban on partial-birth abortions when he served in the Illinois legislature and condemned the Supreme Court decision that upheld legislation banning this heinous practice. He has referred to a baby conceived inadvertently by a young woman as a 'punishment' that she should not endure. He has stated that women's equality requires access to abortion on demand. Appallingly, he wishes to strip federal funding from pro-life crisis pregnancy centers that provide alternatives to abortion for pregnant women in need. There is certainly nothing 'pro-choice' about that.

But it gets even worse. Senator Obama, despite the urging of pro-life members of his own party, has not endorsed or offered support for the Pregnant Women Support Act, the signature bill of Democrats for Life, meant to reduce abortions by providing assistance for women facing crisis pregnancies. In fact, Obama has opposed key provisions of the Act, including providing coverage of unborn children in the State Children's Health Insurance Program (S-CHIP), and informed consent for women about the effects of abortion and the gestational age of their child. This legislation would not make a single abortion illegal. It simply seeks to make it easier for pregnant women to make the choice not to abort their babies. Here is a concrete test of whether Obama is "pro-choice" rather than pro-abortion. He flunked. Even Senator Edward Kennedy voted to include coverage of unborn children in S-CHIP. But Barack Obama stood resolutely with the most stalwart abortion advocates in opposing it.

It gets worse yet. In an act of breathtaking injustice which the Obama campaign lied about until critics produced documentary proof of what he had done, as an Illinois state senator Obama opposed legislation to protect children who are born alive, either as a result of an abortionist's unsuccessful effort to kill them in the womb, or by the deliberate delivery of the baby prior to viability. This legislation would not have banned any abortions. Indeed, it included a specific provision ensuring that it did not affect abortion laws. (This is one of the points Obama and his campaign lied about until they were caught.) The federal version of the bill passed unanimously in the United States Senate, winning the support of such ardent advocates of legal abortion as John Kerry and Barbara Boxer. But Barack Obama opposed it and worked to defeat it. For him, a child marked for abortion gets no protection-even ordinary medical or comfort care-even if she is born alive and entirely separated from her mother. So Obama has favored protecting what is literally a form of infanticide.

You may be thinking, it can't get worse than that. But it does.

For several years, Americans have been debating the use for biomedical research of embryos produced by in vitro fertilization (originally for reproductive purposes) but now left in a frozen condition in cryopreservation units. President Bush has restricted the use of federal funds for stem-cell research of the type that makes use of these embryos and destroys them in the process. I support the President's restriction, but some legislators with excellent pro-life records, including John McCain, argue that the use of federal money should be permitted where the embryos are going to be discarded or die anyway as the result of the parents' decision. Senator Obama, too, wants to lift the restriction.

But Obama would not stop there. He has co-sponsored a bill-strongly opposed by McCain-that would authorize the large-scale industrial production of human embryos for use in biomedical research in which they would be killed. In fact, the bill Obama co-sponsored would effectively require the killing of human beings in the embryonic stage that were produced by cloning. It would make it a federal crime for a woman to save an embryo by agreeing to have the tiny developing human being implanted in her womb so that he or she could be brought to term. This "clone and kill" bill would, if enacted, bring something to America that has heretofore existed only in China-the equivalent of legally mandated abortion. In an audacious act of deceit, Obama and his co-sponsors misleadingly call this an anti-cloning bill. But it is nothing of the kind. What it bans is not cloning, but allowing the embryonic children produced by cloning to survive.

Can it get still worse? Yes.

Decent people of every persuasion hold out the increasingly realistic hope of resolving the moral issue surrounding embryonic stem-cell research by developing methods to produce the exact equivalent of embryonic stem cells without using (or producing) embryos. But when a bill was introduced in the United States Senate to put a modest amount of federal money into research to develop these methods, Barack Obama was one of the few senators who opposed it. From any rational vantage point, this is unconscionable. Why would someone not wish to find a method of producing the pluripotent cells scientists want that all Americans could enthusiastically endorse? Why create and kill human embryos when there are alternatives that do not require the taking of nascent human lives? It is as if Obama is opposed to stem-cell research unless it involves killing human embryos.

This ultimate manifestation of Obama's extremism brings us back to the puzzle of his pro-life Catholic and Evangelical apologists.

They typically do not deny the facts I have reported. They could not; each one is a matter of public record. But despite Obama's injustices against the most vulnerable human beings, and despite the extraordinary support he receives from the industry that profits from killing the unborn (which should be a good indicator of where he stands), some Obama supporters insist that he is the better candidate from the pro-life point of view.

They say that his economic and social policies would so diminish the demand for abortion that the overall number would actually go down-despite the federal subsidizing of abortion and the elimination of hundreds of pro-life laws. The way to save lots of unborn babies, they say, is to vote for the pro-abortion-oops! 'pro-choice'-candidate. They tell us not to worry that Obama opposes the Hyde Amendment, the Mexico City Policy (against funding abortion abroad), parental consent and notification laws, conscience protections, and the funding of alternatives to embryo-destructive research. They ask us to look past his support for Roe v. Wade, the Freedom of Choice Act, partial-birth abortion, and human cloning and embryo-killing. An Obama presidency, they insist, means less killing of the unborn.

This is delusional.

We know that the federal and state pro-life laws and policies that Obama has promised to sweep away (and that John McCain would protect) save thousands of lives every year. Studies conducted by Professor Michael New and other social scientists have removed any doubt. Often enough, the abortion lobby itself confirms the truth of what these scholars have determined. Tom McClusky has observed that Planned Parenthood's own statistics show that in each of the seven states that have FOCA-type legislation on the books, "abortion rates have increased while the national rate has decreased." In Maryland, where a bill similar to the one favored by Obama was enacted in 1991, he notes that "abortion rates have increased by 8 percent while the overall national abortion rate decreased by 9 percent." No one is really surprised. After all, the message clearly conveyed by policies such as those Obama favors is that abortion is a legitimate solution to the problem of unwanted pregnancies -- so clearly legitimate that taxpayers should be forced to pay for it.

But for a moment let's suppose, against all the evidence, that Obama's proposals would reduce the number of abortions, even while subsidizing the killing with taxpayer dollars. Even so, many more unborn human beings would likely be killed under Obama than under McCain. A Congress controlled by strong Democratic majorities under Harry Reid and Nancy Pelosi would enact the bill authorizing the mass industrial production of human embryos by cloning for research in which they are killed. As president, Obama would sign it. The number of tiny humans created and killed under this legislation (assuming that an efficient human cloning technique is soon perfected) could dwarf the number of lives saved as a result of the reduced demand for abortion-even if we take a delusionally optimistic view of what that number would be.

Barack Obama and John McCain differ on many important issues about which reasonable people of goodwill, including pro-life Americans of every faith, disagree: how best to fight international terrorism, how to restore economic growth and prosperity, how to distribute the tax burden and reduce poverty, etc.

But on abortion and the industrial creation of embryos for destructive research, there is a profound difference of moral principle, not just prudence. These questions reveal the character and judgment of each man. Barack Obama is deeply committed to the belief that members of an entire class of human beings have no rights that others must respect. Across the spectrum of pro-life concerns for the unborn, he would deny these small and vulnerable members of the human family the basic protection of the laws. Over the next four to eight years, as many as five or even six U.S. Supreme Court justices could retire. Obama enthusiastically supports Roe v. Wade and would appoint judges who would protect that morally and constitutionally disastrous decision and even expand its scope. Indeed, in an interview in Glamour magazine, he made it clear that he would apply a litmus test for Supreme Court nominations: jurists who do not support Roe will not be considered for appointment by Obama. John McCain, by contrast, opposes Roe and would appoint judges likely to overturn it. This would not make abortion illegal, but it would return the issue to the forums of democratic deliberation, where pro-life Americans could engage in a fair debate to persuade fellow citizens that killing the unborn is no way to address the problems of pregnant women in need.

What kind of America do we want our beloved nation to be? Barack Obama's America is one in which being human just isn't enough to warrant care and protection. It is an America where the unborn may legitimately be killed without legal restriction, even by the grisly practice of partial-birth abortion. It is an America where a baby who survives abortion is not even entitled to comfort care as she dies on a stainless steel table or in a soiled linen bin. It is a nation in which some members of the human family are regarded as inferior and others superior in fundamental dignity and rights. In Obama's America, public policy would make a mockery of the great constitutional principle of the equal protection of the law. In perhaps the most telling comment made by any candidate in either party in this election year, Senator Obama, when asked by Rick Warren when a baby gets human rights, replied: 'that question is above my pay grade.' It was a profoundly disingenuous answer: For even at a state senator's pay grade, Obama presumed to answer that question with blind certainty. His unspoken answer then, as now, is chilling: human beings have no rights until infancy — and if they are unwanted survivors of attempted abortions, not even then.

In the end, the efforts of Obama's apologists to depict their man as the true pro-life candidate that Catholics and Evangelicals may and even should vote for, doesn't even amount to a nice try. Voting for the most extreme pro-abortion political candidate in American history is not the way to save unborn babies.

Robert P. George is McCormick Professor of Jurisprudence and director of the James Madison Program in American Ideals and Institutions at Princeton University.

This article originally appeared in Public Discourse: Ethics, Law, and the Common Good and is reprinted with permission.