In the 40 years since Roe v. Wade was decided, abortion has become a flashpoint in American politics. And last year, the fight seemed to escalate. Republicans in state legislatures across the country passed onerous restrictions on abortion rights. Utah requires a 72-hour waiting period between choosing the procedure and having it (with counseling in between). Oklahoma and Louisiana require women to hear a fetal heartbeat, often necessitating an invasive transvaginal ultrasoound, and Arizona requires doctors distribute faulty information on the mental health dangers of abortion.

On a national level, Republicans pursued efforts to defund Planned Parenthood over its abortion services — which don’t receive federal funding — and during the presidential campaign, Mitt Romney voiced support for a fetal personhood amendment that would effectively outlaw abortion.

With these laws and proposals, one would think the public is evenly divided on the question. But the fact of the matter is that most Americans support the current regime of legal abortion rights. According to the latest NBC/Wall Street Journal poll, 70 percent of Americans oppose overturning Roe, with a large majority of that group feeling strongly about the issue. Close to a third of Americans (31 percent) feel that abortion should be legal in all cases, and just under a quarter (23 percent) feel that abortion should be legal in most cases.

There aren’t many Americans who oppose abortion in all circumstances. Thirty-five percent feel that abortion should be illegal with exceptions made for rape, incest, and the life of the mother. Which is to say that in total, 89 percent of Americans feel that abortion should be legal in some circumstance. By contrast, only 9 percent of Americans oppose abortion without exceptions. Not for rape, not for incest, not for the life of the mother.

If so many Americans believe abortion should exist on the spectrum of legality, then why has one of our major political parties adopted an uncompromising stance against all abortion rights? Individual Republicans might identify as pro-choice, but the party is committed to an anti-abortion agenda. It’s most likely nominees for the Supreme Court oppose Roe, and its presidential ticket featured an avowedly anti-abortion politician in the form of Wisconsin congressman Paul Ryan. Romney is more of a recent convert, but even he promised to retrench reproductive rights.

The answer, in short, is that social conservatives — who are mostly older and mostly white — make up a disproportionate share of the Republican base. What’s more, organizations like the Family Research Council have the resources to support anti-abortion Republicans, and mobilize activists against those who show more heterodoxy on the issue. As with taxes and the size of government, Republicans have every incentive to take a hard line against abortion rights. As long as that’s true — and as long as some Americans always oppose abortion — the GOP is likely to remain a party committed to dismantling the status quo established by Roe, even if a majority supports that status quo.

Jamelle Bouie is a staff writer at The American Prospect, where he writes a blog.