O'Connor generally dissented from opinions in the 1980s which took an expansive view of Roe v. Wade and criticized that decision's "trimester approach" sharply in her dissent in 1983's Akron v. Akron Center for Reproductive Health. In Planned Parenthood v. Casey, O'Connor's opinion introduced a new test that reined in the unrestricted freedom from regulation during the first trimester as proscribed by Roe v. Wade. Whereas before the regulatory powers of the State could not intervene so early in the pregnancy, O'Connor opened a regulatory portal where a State could enact measures so long as they did not place an "undue burden" on a woman's right to an abortion.""...O'Connor's rulings on the issue of abortion were those that were perhaps most widely considered controversial. In her confirmation hearings and early days on the court, she was carefully ambiguous on the issue, as some conservatives questioned her anti-abortion credentials on the basis of certain of her votes in the Arizona legislature.
Anthony Kennedy, appointed by Reagan, and David Souter, appointed by H.W. Bush, joined with O'Connor and opined abortion was still law of the land.
Now tell me how President Reagan advanced pro-life causes other than not funding abortions in military installations?
it was a different nominating process in the Reagan era and before.
It was far more accademic and dry.
Don’t forget the majority of the lawyer pool is to the left so finding an alito takes conscious effort beyond just numbers.