It is a symptom of something truly momentous afoot. The court and nation appear to be on the cusp of a historic change in direction. If presumptive Democratic nominee Hillary Clinton is elected president in November, the court will take a decisive step to the left for the first time in nearly 50 years.

On the other hand, entrepreneur Donald Trump, the presumptive Republican nominee, has pledged to appoint a justice in line with current conservative thought if he prevails. Nevertheless, if the incorrigibly unpredictable Trump is elected, so many bets will be off the table that any forecasting seem like a fool’s errand.

Since President Richard Nixon took office in 1969, the court has been moving steadily to the right, retrenching from the liberal high-water mark achieved under Chief Justice Earl Warren, who led the court from 1953 until 1969. That was the era during which the Supreme Court enforced, for the first time, a wide variety of federal constitutional limits on the injustices that states could inflict upon minorities—whether in the context of school, work, or the voting booth. It also brought a true revolution in criminal procedure, again by requiring states to abide by newly articulated federal constitutional standards.

In that heady era, some liberals imagined that even the inequitable treatment of rich and poor—through, for instance, the use of local property taxes to fund public schools—would eventually be declared to be a violation of the 14th Amendment’s Equal Protection Clause.

But the Warren Court went too far, the electorate apparently felt. There came a great correction, if not a backlash, as conservative Republican candidates won at the national level, in part by inveighing against liberal judicial overreach. From 1969 through 1991, Republican presidents appointed an astounding ten consecutive Supreme Court justices. Nixon appointed three; Gerald Ford one; Ronald Reagan four; and George H.W. Bush two. Democrat Jimmy Carter had no opportunities during his single term. (Since 1993, Presidents Bill Clinton, George W. Bush, and Barack Obama have each made two appointments.)

In light of the long string of unanswered Republican appointments, it might seem remarkable that the Supreme Court did not move further to the right more quickly than it did. But judges’ behavior is hard to predict, and the Republican Party wasn’t always as conservative or ideological as it has become. Nixon’s appointee Harry Blackmun migrated to the left; David Souter sorely disappointed Bush père; both Lewis Powell, Jr. (Nixon) and Sandra Day O’Connor (Reagan) proved to be pragmatic, compromise-driven moderates; and Ford’s John Paul Stevens metamorphosed into a full-fledged liberal lion.

So it wasn’t until January 2006, when the second President Bush appointed Samuel Alito to replace Justice O’Connor—making Justice Anthony Kennedy, a Reagan appointee, the effective center of the Court—that the fulcrum finally shifted decisively to the right.

In the decade since—right up until Antonin Scalia’s death in February—conservatives have enjoyed a confident (some would say arrogant) majority on all but the handful of social issues on which Justice Kennedy swerved left. (Those included, most dramatically, LGBT rights, but also, as we were reminded over the past two weeks, affirmative action in higher education and, to a degree, abortion rights.)

During its ascendant decade, the conservative majority worked breath-taking changes in the constitutional landscape. It struck down assumptions about campaign finance that had reigned for at least 80 years. It junked the key provision of the crowning achievement of the Civil Rights movement—the Voting Rights Act—and did so just seven years after Congress had nearly unanimously voted to extend it. And it declared, for the first time, that the Second Amendment conferred a constitutional right on individuals (and not merely “militias”) to possess handguns, at least under certain circumstances. (Just to convey how far the pendulum has swung, when I was in law school, from 1979 to 1982, my professors would have considered the current law of the land vis-a-vis the Second Amendment to be not just a minority view, but a crackpot one.)

During this past half century—and especially the last decade—many legal doctrines, like “judicial restraint,” have become so riddled with exceptions and qualifications as to be unintelligible, as their champions and opponents have opportunistically switched sides.

Also, during that decade, a cottage industry has arisen of conservative public interest groups and red-state attorneys general who regularly go to court to challenge major Democratic legislation and regulatory initiatives, confident that their pleas would find five sets of sympathetic ears. Texas attorneys general have sued to invalidate federal initiatives more than 40 times since President Obama took office. And last term, in King v. Burwell, when a conservative public interest group urged the Supreme Court to gut the Affordable Care Act—proposing a far-fetched interpretation that had never been articulated by any legislator, attorney, analyst, pundit, or journalist prior to its enactment—only the defection of Chief Justice John Roberts, Jr., from the conservative faction saved the statute, in a 5-4 vote.

There’s nothing new, and nothing illegitimate, about advocacy groups working behind the scenes to tee up blockbuster cases for a receptive Supreme Court. Equivalent organizations sprang up when liberals were in control, and they liberal versions of these groups will enjoy a renaissance if liberals resume control.

The point is simply to say the poles of the constitutional law world are on the verge of being turned topsy-turvy. And that’s why quaint and principled calls for nonpartisanship are doomed to fall on deaf ears. All that matters right now is brute political power, and getting to that magic number five.

The stakes are just too high.