"For close to two decades after Roe v. Wade, 410 U.S. 113 (1973), the Court gave but slight weight to the interests of the separate States when their legislatures sought to address persisting concerns raised by the existence of a woman’s right to elect an abortion in defined circumstances. When the Court reaffirmed the essential holding of Roe, a central premise was that the States retain a critical and legitimate role in legislating on the subject of abortion, as limited by the woman’s right the Court restated and again guaranteed. Planned Parenthood of Southeastern Pa. v. Casey, 505 U.S. 833 (1992). The political processes of the State are not to be foreclosed from enacting laws to promote the life of the unborn and to ensure respect for all human life and its potential. Id., at 871 (joint opinion of O’Connor, Kennedy, and Souter, JJ.). The State’s constitutional authority is a vital means for citizens to address these grave and serious issues, as they must if we are to progress in knowledge and understanding and in the attainment of some degree of consensus."