Every time there’s a Supreme Court vacancy, I bring this up, but the practice of giving justices lifetime appointments strikes me as deeply unsound. Concerns you might have about justices being unduly influenced by political or financial considerations could be easily met by giving justices a single, non-renewable term of 9 or 10 or 12 years plus a decent pension. You could even lay out a minimum age of 60 or something.
I think this would have two advantages over the present system. One is that the current rule puts undue weight on throwing up young appointees. That wouldn’t be terrible on its own terms, but it combines with the fact that a nominee needs to be qualified to have a terrible distorting influence on the whole legal system. There’s incredible pressure to locate bright, committed fortysomethings and put them on appeals courts precisely in order to build the SCOTUS bench. That then puts pressure on Senators to do things like block Goodwin Liu (and before him Miguel Estrada) in order to prevent that. Fixed terms would solve the problem.
The other is that the current rule generates an awful lot of randomness. The most important consideration for the future of American law is not whether Justice Kagan turns out to be more like Breyer or more like Stevens, it’s whether the seventy-four year-old Antonin Scalia can stay in good health until there’s a Republican in the White House. That’s a weird way to run a legal system, especially because the extraordinary difficulty of amending the constitution gives the Supreme Court power that’s very hard to check. What’s more, we might plausibly see in the near future the situation in which an elderly justice begins to suffer from very serious medical problems but refuses to step down because he or she finds the incumbent president ideologically uncongenial.
A fixed-term system would create a predictable relationship between winning presidential elections and appointing justices, and it could also contain a sensible process for replacing a sick or dead justice.