Nixon was unquestionably anti-abortion. He and his followers derided the left as the party of "abortion, acid, and amnesty."
Rockefeller and Grand-daddy Bush were definitely pro-abort. They were the type of "country-club" Republicans who Nixon had to ride rough-shod over to win the Presidency. They despised Nixon because of his humble background.
Daddy Bush became pro-life only because he knew he needed to be, if he wanted to ride Reagan's coat-tails into the Oval Office.
I believe that W is dedicated to a pro-life position. It may be that this is because he saw how soft his father's support was amongst social conservatives who never quite believed in Daddy Bush's change of heart. I really don't care why. W has walked the walk.
He has also been anything but a country-club Republican in style. Good thing, since there aren't many of them left voting these days, anyway...
In numerous books that he wrote after his fall from the presidency, Richard M. Nixon clearly declared himself "pro-choice" on abortion, the same view later adopted by conservative Republican Senators Barry M. Goldwater and John G. Tower. It was said that in 1972, when abortion was not an issue, that McGovern was more "anti-abortion" than was RN. Abortion was not an issue until after Jan. 22, 1973, when the Right-to-Life Committee was formed.