Three justices will be over 80 years old, when the next president is elected: Ginsberg, Kennedy and Scalia. Also, Breyer will be 78 years old.
Both Ginsberg and Breyer are liberals and Scalia is a conservative.
Kennedy has sided with both liberals and conservatives in a number of narrow decisions. He was nominated to the SC by Reagan. Wikipedia states that in his earlier decisions, he sided most of the time with the conservative faction. Often, he is referred to as the most important justice because of his role as a swing voter. Each side has to convince him to vote their way if their side is to get a majority.
If all are replaced by conservatives, this leaves a court divided 7-2 in favor of conservatives. Remaining liberals would be Sotomayor and Kagan. If all are replaced by liberals, this leaves a court divided 6-3 in favor of liberals. Remaining conservatives would be Roberts, Alito, and Thomas.
None of the elderly justices appear to have any health problems. In fact, they are all incredibly alert, active and brilliant. I was very surprised to learn the age of both Justice Scalia and Breyer.
Now, if the court majority becomes conservative, could they overturn a number of decisions? Could the same happen if liberals are the majority? Maybe, but it will be done sparingly and really dependent on the cases before the court. This is because the court can’t do a re-vote on a particular decision, but must have a case in front of them, which relies on a prior ruling. Then, in deciding the new case, the SC can overturn prior decisions.
Once a case has been decided, a legal precedent has been set. The case becomes part of case law, and all courts in the country must respect the decision. The principle of setting precedents is called “stare decisis” as explained below:
So, how many decisions have been overturned? Wikipedia provides a list, noting there are likely other cases it missed:
The “Obergefell v. Hodges” in 2015, is of course, the gay marriage decision, which overturned Baker v. Nelson (1972). The court had previously ruled that state laws prohibiting gay marriages was legal. Thus, the ruling was overturned 43 years later. A second recently overturned case was again a gay rights case, “Lawrence v. Texas” where the majority struck down state anti-sodomy laws. It was decided by liberal faction, with dissents from four conservative justices.
These are just two examples of liberal justices overturning conservative decisions. If the conservatives become the solid majority, then will they overturn liberal decisions? Certainly, if the right cases come before the court, there could be a number of overturned decisions.