Law professor Erwin Chemerinsky likes the 18-year proposal too. "Eighteen years is long enough to allow a justice to master the job, but not so long as to risk creating a court that reflects political choices from decades earlier," he wrote in 2013.
"The Constitution was written at a time when life tenure meant living into your 50s because that's what life expectancy was," legal analyst Jeffrey Toobin, author of two books on the Supreme Court, has noted. "Thirty-year tenures are not what the framers had in mind."
There's another reason cited for term limits: statistically speaking, people are in much sharper shape mentally in their 40s, 50s and 60s than they are in their 70s, 80s and 90s.
"The history of the Court is replete with repeated instances of justices casting decisive votes or otherwise participating actively in the Court's work when their colleagues and/or families had serious doubts about their mental capacities," professor David J. Garrow of the Emory University School of Law wrote in 2000.
"Contrary to conventional wisdom among legal scholars and historians, a thorough survey of Supreme Court historiography reveals that mental decrepitude has been an even more frequent problem on the twentieth-century Court than it was during the nineteenth," Garrow concluded.
Many politicians are on board with some form of Supreme Court term limit. Republican presidential candidates Mike Huckabee, Ben Carson and Rand Paul have all endorsed it. Even some Supreme Court justices like the idea, at least in theory. Just last month, Justice Stephen Breyer said term limits were an idea he could get behind, provided the limits were sufficiently lengthy.
And there is widespread support for term limits among the general public. In 2015 two-thirds of Americans supported a 10-year term limit on Supreme Court justices, according to a Reuters-Ipsos poll. Only 17 percent said they supported life tenure. 66 percent of Democrats and 74 percent of Republicans supported the proposal - a strong, and rare, show of bipartisanship.
So why haven't term limits happened? Blame the Constitution. Article III states that "the judges, both of the supreme and inferior courts, shall hold their offices during good behavior." That's generally been interpreted to mean that justices get to stay on for life, as long as they behave themselves. So most legal scholars agree that mandatory judicial term limits would require a new Constitutional amendment.
That's a high bar, but not an insurmountable one. Given the broad base of support for term limits at both elite and popular levels, a constitutional amendment on this issue is a lot less far-fetched than on others.
Indeed, the nuts and bolts of such an amendment have already been worked out, in a 109-page article published in the Harvard Journal of Law and Public Policy back in 2006. I'll quote at length from the relevant bits:
Congress and the states should pass a constitutional amendment imposing an eighteen‐year, staggered term limit on the tenure of Supreme Court Justices. Under our proposal, each Justice would serve for eighteen years, and the terms would be established so that a vacancy on the Court would occur every two years at the beginning of the summer recess in every odd‐numbered year. These terms would be structured so the turnover of Justices would occur during the first and third year of a President’s four‐year term.
These ideas have gained a broad base of support in the intervening years, including endorsements from the politicians above and even the creation of an advocacy group called Fix the Court that lobbies for Supreme Court term limits.
But there's widespread skepticism that such an amendment could pass, just because the constitutional amendment process sets such a high bar -- especially when you consider today's hyper-partisan political environment.
Correction: A previous version of this story misstated the name of the group advocating for Supreme Court reform. It is Fix the Court, not Fix the Courts.
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