Roe v. Wade was decided in 1971. That's not too soon after the great realignment from the election of 1964. Some of those Republican appointments like Brennan and Stewart happened well before the realignment. And even then, the author of the opinion was written by Blackmun who was appointed by Nixon. Nixon, the guy who brought us the EPA and many other things the modern Republican party likes to hate. Meanwhile one of the dissents to Roe was written by White who was appointed by JFK.

The parties of 1971 were both very different compared to today. You can't assume that someone active in the party in 1956 (Brennan) holds the same values as what's talked about on OAN today.