Adam Liptak captures the peril for the Court:

For President Trump and for Senate Republicans, confirming Judge Brett M. Kavanaugh as a Supreme Court justice was a hard-won political victory. But for the conservative legal movement, it is a signal triumph, the culmination of a decades-long project that began in the Reagan era with the heady goal of capturing a solid majority on the nation’s highest court.

With Judge Kavanaugh’s swearing-in, that goal has been accomplished, and the Supreme Court will be more conservative than at any other time in modern history. By some measures, “we might be heading into the most conservative era since at least 1937,” said Lee Epstein, a law professor and political scientist at Washington University in St. Louis…

There will be no swing justice in the mold of Anthony M. Kennedy, Sandra Day O’Connor or Lewis F. Powell Jr., who forged alliances with both liberals and conservatives. Instead, the court will consist of two distinct blocs — five conservatives and four liberals. The court, in other words, will perfectly reflect the deep polarization of the American public and political system.

The fight to put Judge Kavanaugh on the court only widened that division. The confirmation process was a bare-knuckle brawl, and the nomination was muscled through by sheer force of political will. All of this inflicted collateral damage on the court, leaving it injured and diminished.

It also left Chief Justice John G. Roberts Jr. in a tricky spot. He will acquire an additional measure of power, taking the seat at the court’s ideological center that had been held by Justice Kennedy, whose retirement in July created the vacancy filled by Judge Kavanaugh. But Chief Justice Roberts may want to use that power sparingly if he is to rebuild trust in an institution that has been discussed for months in almost purely political terms.