Eighty-four-year-old Republican Senator (and Chair of the Senate Judiciary Committee) Charles Grassley raised some eyebrows, and some hackles, when he suggested quite publicly last week that any Supreme Court justice who might be contemplating retirement should do so sooner, rather than later. As Senator Grassley put the point in an interview: “I just hope that if there is going to be a nominee, I hope it’s now or within two or three weeks, because we’ve got to get this done before the election . . . . . So my message to any one of the nine Supreme Court justices, if you’re thinking about quitting this year, do it yesterday.”

Although Grassley’s remarks were ostensibly framed to address all nine justices, his audience was clearly Justice Anthony Kennedy (whose possible retirement timeline has been a source of much speculation over the last year) or any other conservative-leaning justice. This ideological slant was not lost on Democrats in the Senate. “There is no principled stand. They will use whatever rationale they find expedient. There’s no conviction or principle to this. There’s no method to the madness,” fumed Connecticut Democratic Senator Richard Blumenthal.

The Dems’ frustration in this arena is understandable given the hardball tactics that Senator Grassley and other Republicans employed in denying a hearing or a vote on Judge Merrick Garland, President Obama’s nominee to fill the vacancy created by the sudden death of Justice Antonin Scalia in February 2016. In some respects, the Garland affair—and the Republicans’ understandable fear that if Democrats regain the Senate this fall they would rely on the Garland precedent to refuse President Trump the ability to fill any Court vacancy in 2019 or 2020—makes Grassley’s exhortation surprising only in its directness. Democratic Senate leader Dick Durbin from Illinois suggested as much when he observed: “[I]n light of what happened to Merrick Garland I think Republicans ought to think twice. . . . [Senator Grassley’s comments are] a signal that they are worried about future control of the Senate in light of a Supreme Court vacancy.”

Yet moving beyond skirmishes of the last few years, Senator Grassley was just making explicit a failure in the current federal judicial selection system that has been known to careful observers for a few decades now. Ironically, while so-called life tenure for federal judges (including and perhaps especially Supreme Court justices) was intended to insulate federal judges from politics so that they will act apolitically in deciding cases, in reality life tenure encourages Supreme Court justices to be overly mindful of politics—in particular the partisan political landscape of the White House and the Senate—in deciding when to retire.

Consider, for example, that we have to go back almost three decades—to 1991—to find a justice (Thurgood Marshall) who retired during the term of a president who was clearly ideologically opposed to the philosophy of the retiring justice. And the four most recent retirements (by Justices Blackmun, O’Connor, Souter, and Stevens) all seem to have been consciously timed to cede a Court seat from a justice to a like-minded president. The nomination and confirmation processes have become less principled and more partisan, and it is hard to avoid the suspicion that the justices themselves are playing this game and getting sucked into partisan politics. And even if the incentives and motivations I describe don’t actually affect judicial resignation decisions in the slightest, the public perception of their doing so is inescapable, and creates costs of its own. In case after case about judicial ethics, the justices express worry about not just about the reality of judicial impartiality but also its appearance.

Here are some additional facts about modern Supreme Court vacancies. Between 1789 and 1970, the average time between Supreme Court vacancies was 1.93 years; between 1971 and 2000, it went up about 50% to 2.98 years. The big reason for that, of course, is that justices are living—and thus serving—much longer. The average age at departure for Supreme Court justices from 1789 to 1970 was 68.5 years; whereas from 1971 to 2000, it was 78.8 years. From 1789 to 1970, the average justice served on the Court 15 years, whereas from 1971 to 2000, justices who left had served an average of a whopping 25.5 years. And that number has only gone up since 2000. For these and other reasons, presidents have incentives and an increasing tendency to pick very young—and stealth—Supreme Court candidates in order to extend their legacy as much as possible.

I am not suggesting here that the mode used by many states to pick high court judges—judicial election models—is superior to the federal approach. As Justice O’Connor in particular has pointed out since her retirement from the Court, there are deep—perhaps intractable—problems with electing judges the way we do legislators and chief executive officials. But the fact that virtually no state has emulated the federal system here does illustrate that the federal method—that Justice O’Connor and other critics of judicial election hold out as the way to go—itself hasn’t worked out optimally the way the framers might have hoped.

Yet is there a third way? Perhaps the problem of injecting too much partisan politics into the judicial world and the problem of justices being entrenched for decades and decades would both be mitigated if we moved to fixed terms—perhaps of 18 years—for each justice. Under such a system, each justice would move off the Court when the 18 years were up—regardless of who occupies the White House. And each justice would be much more constrained in her ability to serve on the Court many years after the world that generated her appointment has gone away.

Importantly, amending the Constitution right away to accomplish these salutary objectives may not be necessary. A clever statutory solution—pioneered by legal scholars such as Roger Cramton and Paul Carrington over the past few decades—might satisfy the Constitution. Under the statute, judges would technically sit on the Supreme Court “by designation” for a fixed number of years (again, say 18 years) after which they would have the option to serve the remainder of their life tenure on some lower federal court. The justices would remain federal judges with life tenure—but not all of that tenure would be served on the Supreme Court. And any such approach may also benefit the lower federal courts, by having former Supreme Court justices sharing their talents and experiences with the judges whose decisions are reviewed on high.

Other non-constitutional fixes may also be possible. The Senate could insist that all future Court nominees publicly agree to term limits, or risk non-confirmation. While legally unenforceable, such commitments by justices would likely be honored. And unlike promises to rule certain ways on certain cases—which I have criticized harshly in other essays—a term-limits pledge would not present concerns of judicial independence or due process. Congress could also restructure salaries, pensions, office space, and other perks to give future justices incentives to live by their word.

It would be crucial that any changes be completely prospective rather than retrospective: they should be applicable only to the future nominees of both parties and all ideologies, and to no present sitting justices. This will avoid any perception that the term limits idea is being used to oust disliked current justices. Indeed, ideally, politicians should declare their preference for Supreme Court term limits before the next Court vacancy comes up, so as to avoid even the appearance of outcome-manipulation. And if this new regime were to be implemented only down the road, this should be an issue on which the parties can agree.

Of course, even with such a system in place, justices could still act strategically by leaving before their 18 years were up, if to do so would be to give their seats to “friendly” presidents and Senates. But presidents could do the same thing: Presidents Reagan and Clinton could have resigned in the last years of their second terms to give their vice presidents the mantle of incumbency when those vice presidents themselves ran for the White House the next year. If overtly political presidents can be encouraged not to act in this manipulative way, surely we can hope for and expect the same grace from our Supreme Court justices. The larger point is that we should think about ways to work within the Constitution itself. The congressional fix mentioned above—and perhaps an alternative, or complementary, solution in which Court itself develops some of its own retirement guidelines to change the culture and tradition of the place—could be just as effective as a ramped-up amendment process. All of this is a good reminder that there is often more than one way to get where you want to constitutionally go.