Less than a week before the 40^th anniversary of the Supreme Court’s landmark Roe v. Wade decision, a new survey finds that a solid majority (63%) of Americans oppose overturning the ruling. Support for Roe v. Wade, which ensconced a woman’s constitutional right to abortion during the first trimester of pregnancy, has remained steady over the past two decades. But the anniversary raises interesting questions about the availability of abortion in America, as well as the extent to which the pro-life movement is succeeding in getting state legislatures to enact significant restrictions on abortion, even as the procedure remains legal.

The convergence of two important factors helps explain the success of state-level abortion restrictions: the sustained engagement and enthusiasm of the pro-life base, combined with declining public interest in – and ongoing ambivalence about – the abortion issue. Overall, less than 1-in-5 (18%) Americans report that abortion as a critical issue, compared to 28% in 2006. But enthusiasm remains strong among the anti-abortion camp: opponents of Roe v. Wade are more than four times as likely as the ruling’s supporters to say that abortion is a critical issue (38% vs. 9%).

Meanwhile, although the general public remains supportive of legal abortion in at least some cases, the general public remains more likely to say abortion is morally wrong (47%) than to say it is morally acceptable (13%), or to say that it is not a moral issue (27%). Approximately 1-in-10 (9%) say it depends on the situation. The popularity of many abortion restrictions likely stems from the restrictions’ rhetorical focus on safety and morality, rather than legality. Currently, 39 states require an abortion to be performed by a licensed physician, 19 states have laws in effect that prohibit “partial-birth” abortions, 17 states mandate that women be given counseling before an abortion, and 26 states require a woman seeking an abortion to wait a specified period of time. These laws make it more difficult for women to access abortion without infringing on its legality, couching their language in terms of the woman’s safety rather than abortion’s permissibility.

Paradoxically, it is precisely because the pro-life movement has failed to overturn Roe v. Wade that it has had so much success enacting restrictions at the state level. As the past election cycle shows, declaring opposition to abortion in circumstances like rape can end a political campaign, although there are a handful of members of Congress who continue to hold these views. A significant threat to the legal framework established by Roe would very likely increase the level of engagement of a public that supports legalized abortion in at least some circumstances. As long as restrictions do not undermine abortion’s legality, and focus instead on limiting the circumstances under which abortion can be accessed, it is unlikely to galvanize the majority of Americans who support Roe – but who remain conflicted abortion’s morality.