"Though Justices O’Connor, Kennedy, and Souter declined in Casey, on the ground of stare decisis, to reconsider whether abortion enjoys any constitutional protection, 505 U.S., at 844—846, 854—869 (majority opinion); id., at 871 (joint opinion), Casey professed to be, in part, a repudiation of Roe and its progeny. The Casey joint opinion expressly noted that prior case law had undervalued the State’s interest in potential life, 505 U.S., at 875—876, and had invalidated regulations of abortion that “in no real sense deprived women of the ultimate decision,” id., at 875. See id., at 871 (“Roe v. Wade speaks with clarity in establishing … the State’s ‘important and legitimate interest in potential life.’ That portion of the decision in Roe has been given too little acknowledgment” (citation omitted)). The joint opinion repeatedly recognized the States’ weighty interest in this area. See id., at 877 (“State … may express profound respect for the life of the unborn”); id., at 878 (“the State’s profound interest in potential life”); id., at 850 (majority opinion) (“profound moral and spiritual implications of terminating a pregnancy, even in its earliest stage”). And, the joint opinion expressed repeatedly the States’ legitimate role in regulating abortion procedures. See id., at 876 (“The very notion that the State has a substantial interest in potential life leads to the conclusion that not all regulations must be deemed unwarranted”); id., at 875 (“Not all governmental intrusion [with abortion] is of necessity unwarranted”). According to the joint opinion, “The fact that a law which serves a valid purpose, one not designed to strike at the right itself, has the incidental effect of making it more difficult or more expensive to procure an abortion cannot be enough to invalidate it.” Id., at 874. The Casey joint opinion therefore adopted the standard: “Only where state regulation imposes an undue burden on a woman’s ability to make this decision does the power of the State reach into the heart of the liberty protected by the Due Process Clause.” Ibid. A regulation imposes an “undue burden” only if it “has the effect of placing a substantial obstacle in the path of a woman’s choice.” Id., at 877."