On Wednesday, Alabama outlawed nearly all abortions, with a prison term for doctors of up to 99 years. Sponsors and supporters of the new law are promoting it as a challenge to Roe v. Wade. But politically, it’s a disaster. By prohibiting abortions even for rape survivors, the law threatens to antagonize the public and shatter the Republican base.

Banning abortion is unpopular to begin with. Many Americans who dislike abortion don’t want it to be prohibited. Normally, they vote on other issues. But when Roe looks shaky, they get scared and vote against politicians who threaten to criminalize the procedure. If you’re looking for a single event that could ignite a backlash against Republican candidates, an overturn of Roe is high on the list.

The Alabama law is even more incendiary. Alabama lawmakers rejected an amendment that would have exempted women who become pregnant by rape. When you extend a ban to these women, you cut the anti-abortion constituency in half. You take an idea that already scares and angers many people—banning abortions generally—and make it absolutely toxic. In particular, you alienate voters on the right who distinguish rape survivors from women who chose to have sex. By forcing victims to bear the offspring of their predators, you offend the morals of law-and-order conservatives.

This isn’t just speculation. Through the General Social Survey, a massive public opinion database built by NORC at the University of Chicago, you can see how themes of sex, crime, and punishment affect the abortion debate. One regular question on the GSS asks whether “it should be possible for a pregnant woman to obtain a legal abortion if the woman wants it for any reason.” On average, over the course of four decades, 39 percent of respondents have said yes, and 57 percent have said no. The most recent GSS sample, taken in 2018, was evenly split, 49 percent to 49 percent.

When you bring up rape, however, the anti-abortion constituency plummets. Since 1972, the GSS has asked whether “it should be possible for a pregnant woman to obtain a legal abortion if she became pregnant as a result of rape.” In the multiyear average, 78 percent of respondents have said yes, and 18 percent have said no. In the survey’s most recent sample, taken last year, 76 percent said yes, and 21 percent said no. So when the debate shifts to women who became pregnant by rape, abortion opponents lose more than half of their audience, and on average about two-thirds.

Only 30 percent of conservatives reject Alabama’s position on unrestricted abortion, but another 40 percent reject Alabama’s position on rape.

In particular, they lose the support of conservatives. By a ratio of roughly 3 to 2, people who say that abortion should be permitted for any reason are more likely to identify themselves as liberal than as conservative. But when you ask about rape, the balance shifts. Among people who are open to an abortion ban in theory—that is, people who believe some reasons for abortion are unacceptable—those who say that the procedure should be available to rape victims are, by a ratio of 5 to 3, more likely to identify as conservative than as liberal. In short, when you extend an abortion ban to rape victims, you split the Republican base.

The cumulative effect is devastating. Only 30 percent of conservatives reject Alabama’s position on unrestricted abortion, but another 40 percent reject Alabama’s position on rape. Adding rape survivors to an abortion ban cuts the support level of conservatives, based on GSS data, from about two-thirds to one-quarter.

Why do so many conservatives demand a rape exception? One reason has to do with sex. A lot of people think that women who choose to have intercourse should bear the consequences, including motherhood. But rape victims didn’t choose to have sex. So it’s unjust, from this perspective, to make such women carry their pregnancies to term.

You can see this mentality at work in the GSS. One question in the survey asks, “If a man and woman have sex relations before marriage, do you think it is always wrong, almost always wrong, wrong only sometimes, or not wrong at all?” Over the four-decade average, 35 percent of people have said it’s always or almost always wrong. Let’s call those people sexual conservatives. At the other end of the spectrum, 43 percent of respondents have said it’s not wrong at all. Let’s call those people sexual liberals. (Lately, the numbers have shifted to the left. In 2018, 24 percent of people said premarital sex was always or almost always wrong, while 61 percent said it wasn’t wrong at all.)

On abortion, sexual conservatives differ from sexual liberals in ways that resemble the gap between political conservatives and political liberals. On the initial question—whether abortion should be allowed for any reason a woman chooses—sexual liberals are far more likely than sexual conservatives to say yes. Only 16 percent of people who say yes to this question are conservative on premarital sex. Four times as many, 64 percent, are liberal on premarital sex. But when you advance to the second question—whether abortion should be available to survivors of sexual assault—the gap disappears. Among people who agree that there should be limits on the permitted reasons for abortion, those who support abortion for rape victims are as likely to oppose premarital sex as to defend it.

Again, the cumulative political effect is disastrous. On the first question—whether pregnancies can be terminated for any reason—abortion opponents lose 17 percent of sexual conservatives. But on the rape question, they lose another 43 percent. They end up with the support of barely one-third of this core Republican constituency.

Across the political spectrum, Americans express more sympathy for rape victims than for women seeking abortions for other reasons. When GSS respondents are asked about various scenarios, they’re far more willing to grant an abortion if the woman has been raped than “if she is married and does not want any more children” or “if the family has a very low income and cannot afford any more children.” Among liberals, the sympathy gap between these scenarios is about 20 points. Among conservatives, it’s 30 to 40 points.

Sex explains only part of the conservative defection on abortion for rape victims. Another factor is crime. Most people on the right believe in law and order. They think that the innocent should be spared and the guilty should be punished. And they’re less moved by the idea of an innocent embryo than they are by the outrage of making a victim bear her assailant’s child.

This psychology, too, can be detected in the GSS. The survey asks, “In general, do you think the courts in this area deal too harshly or not harshly enough with criminals?” Over the course of nearly half a century, the share of respondents who say “not harshly enough” has dwarfed the share who say “too harshly,” 73 percent to 7 percent. More recently, the gap has subsided. In 2018, 54 percent of respondents said courts weren’t harsh enough. Eighteen percent said they were too harsh.

On the question of abortion for any reason, 60 percent of law-and-order conservatives—those who say courts don’t deal harshly enough with criminals—support the anti-abortion position. But when the discussion turns to rape cases, most of these supporters drop out. Only 18 percent of law-and-order conservatives agree that abortions shouldn’t be permitted for women who became pregnant by rape. Politicians who seek to outlaw abortion lose more of this constituency on the second question than on the first.

In fact, when you measure respondents by their views on crime, the inclusion of rape victims alienates more people on the right than on the left. On the question of abortion for any reason, people who say courts aren’t harsh enough support the anti-abortion position, while people who say courts are too harsh divide almost evenly. But when the rape question is put to people who think there should be limits on the permitted reasons for abortion, those who say courts don’t deal harshly enough with criminals are more likely than their liberal counterparts to reject the anti-abortion position. The idea of making a woman carry a rapist’s child offends them.

I understand why some anti-abortion lawmakers refuse to make an exception for rape. If you truly believe that every human embryo is a person, then that person’s life should be protected, regardless of how he or she was conceived. But politically, the Alabama ban is catastrophic. If it becomes the focus of the national abortion debate, it won’t just mobilize people who believe in women’s rights. It will alienate people who believe in punishing criminals and protecting their victims. It will turn conservative America against itself.