I would argue that the amount of emphasis the public places on the Supreme Court to decide things their way is what has changed. I can't say what things were like 50-100 years ago but I don't think people placed as much emphasis on having the Supreme Court make policy as they have in the last few decades.
Dredd Scott - 1857 - Blacks who's ancestors were brought to the US as slaves are not citizens themselves, and have no standing to sue anyone. Also slaves are property, and no law can be made depriving someone of their property.
Homer Plessy - 1896 - Finding that "separate but equal" does not violate the constitution so segregated accommodations were perfectly fine.
Abrams v US - 1919 - Finding that "disloyal language" was not protected free speech and therefore anti-war activists can in fact be jailed under the Espionage Act.
Commonwealth of Massachusetts v. Mellon - 1923 - Finding that taxpayers don't have standing to sue over what their taxes go for (someone sued because the feds started funding health services for mothers and infants).
Buck v. Bell - 1927 - Finding that forced sterilization of mentally incompetent people was perfectly fine and legal.
Near v. Minnesota - 1931 - Finding that the press is in fact free and can say what it wants, regardless of whether politicians like it or not.
Brown v. Board of Education - 1954 - Finally finding that "separate but equal" was not in fact constitutional and desegregating schools.
Engel v. Vitale - 1962 - Finding that forced prayer in public schools is in fact unconstitutional, since it's a branch of the government "establishing a religion".
Gideon v. Wainwright - 1963 - Establishing a public defender as a basic right.
Reynold v. Sims - 1964 - Requiring legislative districts to be of equal population.
Heart of Atlanta Motel v. US - 1964 - Establishing that the Civil Rights Act was in fact constitutional.
Miranda v. Arizona - 1966 - Where the "Miranda Rights" come from.
Loving v. Virginia - 1967 - Striking down bans on interracial marriage.
Terry v. Ohio - 1968 - Establishing the "probable cause" metric for police searches.
Brandenburg v. Ohio - 1969 - Establishing that speech is free even when it comes from Nazis' and the KKK and that you can only prosecute people for directly inciting "imminent lawless action".
Phillips v. Martin Marietta Corp. - 1971 - Finding that family status (like whether you have kids) is part of the Civil Rights Act and therefore you can't discriminate by that criterion.
Wisconsin v. Yoder - 1972- Finding that the state can't force your kids to go to school if it's against the parent's religion.
Roe v. Wade - 1973
These are all 47-163 year old cases, and they're just ones I picked from a list after a quick google. I think it's a completely baseless assumption that the court "didn't used to be politicized as much", do you have any evidence of that?