No one should begrudge Kennedy a well-earned retirement. But let's be clear: His departure will change the court and hurt the country.
We've said before that Sen. Claire McCaskill and Attorney General Josh Hawley should make their views on the court and its judges crystal clear during the coming Senate campaign. That suggestion still applies. McCaskill and Hawley must put the court's role at the center of their discussions with Missouri voters.
That means answering specific questions about the court's rulings, and the philosophy of judges on the federal bench.
It's increasingly clear the Supreme Court is the most important actor on fundamental issues of American life. Free expression, human rights, equality, religion, campaign finance, gun rights and voting rights, are all on the court's docket.
The impotence of the legislative branch and the incoherence of the executive branch have thrown many of the toughest issues into the laps of nine unelected justices.
But it's also clear the court has all but abandoned any pretense to following the rule of law, or precedents, or any consistent legal theory at all. Just Wednesday, the court tossed aside decades of precedent to say public employees need not contribute to unions that represent their interests.
The vote, naturally, was 5-4. "There is no sugarcoating today’s opinion," wrote Justice Elena Kagan in a dissent. "The majority overthrows a decision entrenched in this Nation’s law — and in its economic life — for over 40 years ... because it wanted to."
Every American should regret the court's slide into naked partisanship. But citizens should also be prepared for reality: President Donald Trump will certainly nominate a conservative to replace Kennedy, and the Republican-controlled Senate could ram the choice through without serious consideration or debate this fall.
We'd urge McCaskill to slow down the process, but there is little she can do. The filibuster for Supreme Court justices no longer applies. Unless moderate Republicans of good faith step forward - always a possibility - the court's rightward tilt will continue, perhaps for decades to come.
That will provide aid and comfort to Senate Majority Leader Mitch McConnell, who swiped a court pick from former President Barack Obama. But imagine the elation of Kansas Secretary of State Kris Kobach: His disastrous voter registration program is now one step closer to a favorable Supreme Court review.
The Supreme Court's role as a last-resort defender of the rule of law will continue to erode. Justice Kennedy's retirement assures that outcome - and serves as a reminder, as if we needed it, that votes matter.