Why not 20 year limits?
The founding fathers thought that the US constitution would look like the UK. President = King, Congress = Parliament. The judiciary was practically an afterthought, and like UK courts, would be subordinate to Congress. “ In all Cases affecting Ambassadors, other public Ministers and Consuls, and those in which a State shall be Party, the supreme Court shall have original Jurisdiction. In all the other Cases before mentioned, the supreme Court shall have appellate Jurisdiction, both as to Law and Fact, with such Exceptions, and under such Regulations as the Congress shall make.”
Note the “such exceptions and under such regulations”.
As history turned out, Congress has barely used this power to rein in the courts and in the mid-19th century on the courts grew more and more powerful and have become a sort of mini-legislature.
James Madison already recognized this, writing in 1788 that he realized a mistake had been made in the constitution: “ as the Courts are generally the last in making their decision, it results to them, by refusing or not refusing to execute a law, to stamp it with its final character. This makes the Judiciary Dept paramount in fact to the Legislature, which was never intended, and can never be proper ... ” (https://press-pubs.uchicago.edu/founders/documents/v1ch17s25...)
https://clickamericana.com/topics/health-medicine/us-life-ex... https://www.everydayhealth.com/senior-health/what-life-expec...
Those probably aren't the best places for me to get numbers, but I think they're good enough for a rough example of what I mean.
I used the historical list of US Supreme Court justices [0] and averaged the lifespan of the first 20 justices. The average was 67 years. Maximum was 91 [1].
[0] https://en.wikipedia.org/wiki/List_of_justices_of_the_Suprem...
This is false. The statistic doesn't imply this. Longevity has not increased significantly, it's that life expectancy from birth has increased because childhood illness became less of a concern. Once at adult age people generally still lived long, ignoring accidents which really wouldn't be a concern for the type of people who would be justices.
It is not like people dropped dead at 50. People who survived usually hit their 70s even when the expectancy was in 30s and 40s. The average is low because lot of kids and people died young.
The proper metric here would be life expectancy of active lawyers/judges in their 30s and 40s . They have double advantage of both generally surviving all the diseases till then and wealthy and educated enough to afford medical care available.
Even if the idea was that people may not survive long, it is a unpredictable and inconsistent way to set policy.
The idea is similar to tenure. You can do and say what you believe without influence and pressure from either party. It also dodges influence peddling preparing for leaving office. For example, in the defense department, officials will make recommendations and then leave office and profit from those same companies. If you're in office for life, this common (and almost impossible to prevent) kind of corruption becomes basically a non issue.
The federalist papers would shed light on such things, but actually reading them (and the wealth of nations)is likely to turn you into an independent who dislikes both parties.
Both parties are a blight that should never have gotten enshrined the way they are.
The last 4+ justices appointed were in their 50s. Gorsuch was 50. A top name on the short list both times was Amy Coney Barett, 48. They've been grooming a 38 year-old, Justin Walker, for the court. He went from a few months of litigation experience to the federal bench to the DC circuit in a year.
Notice how all these people also look very healthy? They're trying to get people who will last a lot longer than 20 years.
https://en.wikipedia.org/wiki/Supreme_Court_of_Justice_of_th...
I'd add the requirement of at least a year of criminal defense experience since this is almost completely lacking currently and it shows in the horrible decisions the court makes.
It also makes sense. Cognitive ability deteriorates with age. And you don't want very old, with illness to rule on important things.
The idea behind no term limits is, the judge can choose to retire doesn't have to.
You have invested a lot of effort in getting a judge to the top as a country. you don't necessarily need a arbitrary date to retire.
Each individual has a capacity to serve upto different age unique to them. Setting a common age for all is not efficient, plenty of judges for example are employed in india post 65, in arbitration and government commissions.
It makes sense not have term limits when the court size is small.
The problem for america is that everything is political: judges and their retirement . In a 2 party first past the post/ winner takes all system that is inevitable.
There are a lot of unplugged holes in the constitution. This is just another issue...