Dan McLaughlin of National Review Online argues in favor of a new age limit for people holding top federal government offices.

For now, the Constitution provides no limit on how old any of these people can grow to be while still serving full-time in highly demanding jobs with weighty responsibilities to the public. When the Constitution was written, there was little reason to consider such limits, because even those who escaped early death rarely lived many years after their faculties seriously declined. Given the late development of modern medicine, that remained true until well into the 20th century. …

… While gerontocracy has not produced good governance — with ageing leaders being especially hesitant to worry about the long-term fiscal sustainability of the federal budget — we have thus far avoided a major crisis. We may not always be so fortunate. I do not believe in adding term limits to the Constitution (that’s another day’s argument), but we ought to add an upper age limit in order to head off crises before they happen and hopefully, at the margins, encourage some new blood. Some of us might even live to see a president born after 1949 again before we die.

It is true that age is an imperfect proxy for the capacity to do the job, but the advantage of bright-line rules is that they are all but self-enforcing in a way that is impersonal and bipartisan. Removing a president or a Supreme Court justice from office on grounds of mental or physical unfitness would instigate a titanic political power struggle; doing so because they’d hit a constitutional age limit would be a routine thing. Many state courts, for example, already have mandatory retirement ages.

Adding such limits is likely to save us more grief than it will cost us in the services of wise old heads. As Nate Silver details, there is powerful statistical evidence of the dramatic rise in the risk of death and/or dementia, at least in men, as we move into our early and mid 80s.