WHO will guard the guardians? When Juvenal, the Roman poet, asked this question twenty centuries ago, he was worried about cheating wives. Today, the query is being posed to the elderly judges of America’s highest court. David Garrow, a law and history professor at the University of Pittsburgh School of Law, reminds us in an op-ed at the Los Angeles Times that the Supreme Court has never been older. The baby on the bench is Justice Elena Kagan at 55, now serving her sixth Supreme Court term. Her fellow Barack Obama appointee, Sonia Sotomayor, is 61—as is the chief justice, John Roberts. Conservative justices Samuel Alito and Clarence Thomas are 65 and 67. From there the bench turns decidedly geriatric. Stephen Breyer is now 77 and Anthony Kennedy is 79. The ideologically incompatible opera-loving buddies Antonin Scalia and Ruth Bader Ginsburg are the oldest justices. Both are celebrating birthdays next month; he is turning 80, she 83.
 
The constitution says that federal judges hold their offices “during good behaviour”, which means as long as they like, barring death (ending the careers of 49 justices) or impeachment. Only one Supreme Court justice, Samuel Chase, was ever impeached, in 1804. But he was acquitted by the Senate and so remained in office until his death in 1811. The “good behaviour” standard is rather toothless, as the case of Justice William O. Douglas illustrates best. Justice Douglas, who donned the black robe from 1939 to 1975, spanning administrations from Franklin Delano Roosevelt to Gerald Ford, resisted efforts from his brethren to step down after he suffered a disabling stroke in 1974. It took 11 months for his colleagues to persuade him to retire, but Douglas continued to try to insert himself into court business even after he had been replaced by another long-serving justice, John Paul Stevens. Neither Mr Douglas’s wheelchair nor his addled right hemisphere deterred him from trying to continue to serve the institution where he had worked for nearly 37 years.

In his op-ed, Mr Garrow proposes that Chief Justice Roberts follow the lead of the 9th Circuit Court of Appeals, where a programme is in place to watch for cognitive decline and encourage judges to remove themselves from the bench before they start to show signs of forgetfulness or confusion during hearings. The appeals court, according to a US News report last year, “holds regular seminars led by neurological experts to teach its chief judges about the signs of cognitive impairment” and has a “hotline where court staff and judges can get advice about dealing with signs of senility in colleagues”. Judges in the 9th circuit are also “encouraged...to undergo cognitive assessments and designate colleagues, friends or family who can intervene if concerns arise about their mental health”. As head of the federal courts, Mr Garrow writes, the chief justice has the authority “to require his high court colleagues and others to undergo regular mental health checkups”.
 
It is doubtful that John Roberts would deign to assert the authority to make regular psychological screenings mandatory for federal judges. The constitution is largely silent on what the office of the chief justice entails, conferring exactly one specific power on the holder of the gavel: “When the President of the United States is tried, the Chief Justice shall preside". Yet yearly checkups for the justices couldn’t hurt; early dementia and cognitive decline are notoriously difficult to detect on your own. The chief justice could encourage the guardians to watch over themselves more closely. And, as Mr Garrow suggests, he could “recommend a judicial retirement age of 70 or 75” as many other countries and most states in America do, and “could even pledge to serve for no more than 18 years”.
 
For all the virtues of these ideas, they may be a lot to ask of a youthful chief justice whose first decade holding the gavel just passed in a flash: he is unlikely to want to voluntarily clip his own tenure short.
 
Watching the rather ancient justices at work these days is not to witness scenes out of a nursing home, despite some notorious nodding off during recent state of the union addresses. Justices Breyer and Kennedy are active, searching, well-prepared questioners during oral arguments. Justice Scalia might be less tempered and he’s certainly ruder than ever, but, judging by his opinions and his public appearances, his crotchety character does not seem to stem from an intellectual decline. Justice Ginsburg’s tiny frame and tinier voice actually seem a bit more robust this year than in recent terms, and her characteristically incisive command of the issues is undulled.
 
To say that everything is rather swell among the current aging justices is not to say that the founders envisioned this extreme of what Alexander Hamilton calleda superannuated bench”. The whole purpose of life tenure is to remove judges from the rough-and-tumble world of politics and give them the independence necessary to adjudicate disputes fairly and objectively. The idea was not to let individuals reign over the American polity for the better part of four decades. But given how difficult it is to amend the constitution, Americans may be stuck with old judges for quite a while. One hopes the jurists will have enough judgment to police themselves, and each other, as their hair grows greyer and sparser.