Senate Majority Leader Mitch McConnell has changed the Supreme Court for good. On Thursday, Democrats successfully filibustered President Donald Trump’s nomination of Neil Gorsuch, the 49-year-old arch-conservative from the Tenth Circuit Court of Appeals in Denver, Colorado. Senate Republicans responded by changing the rules to require only a simple majority to confirm Supreme Court nominees, which was already the rule for all other federal judicial appointments. The immediate outcome was bad: Gorsuch was confirmed to a lifetime appointment to the Court on Friday. In the long term, the battle over Gorsuch reflects a new era in which Senate deference to judicial nominations is over, possibly with more sea changes to come.

We should be clear that Senate Democrats did the right thing by filibustering Gorsuch. If a simple majority for Supreme Court nominations is going to be the new norm—and it clearly is—it is better that this be done explicitly and immediately. Democrats had absolutely nothing to gain by pretending that the previous norms held, particularly after the refusal of Republicans to consider former President Barack Obama’s nominee Merrick Garland to replace Antonin Scalia. It was guaranteed that Republicans would nuke the filibuster for another Republican nominee—or exploit the filibuster for a Democratic one.

The end of the filibuster was the culmination of a long process. Republicans are inclined to blame the defeat of Robert Bork by a Democratic Senate in 1987, but this is misleading—Bork was given a full up-or-down vote, and after he was rejected the Senate quickly confirmed a more moderate nominee, Anthony Kennedy. The Bork nomination did not destroy the norm of deference to the president’s choice for the Supreme Court.

Rather, what contributed to a culture of obstruction was the rejection of lower-court nominees, which began with Republicans under Bill Clinton, escalated with Democrats under George W. Bush, and escalated even further with the Republican minority under Obama. The key was the failure of the so-called “Gang of 14” deal under Bush that allowed a large number of Bush nominees—including some genuine extremists like Judge Janice Rogers Brown—to be seated. It preserved the filibuster for judicial nominees with a promise to use it only in “extraordinary circumstances.” But as soon as Obama was elected these circumstances turned out to be “any nominee Republicans don’t like, regardless of their qualifications.”

Trump’s nominee was about as far from a consensus nominee as you could get, a sop to the hard right.

Senate Republicans refused to consider any Obama nominee to the nation’s second-most powerful court, the U.S. Court of Appeals for the District of Columbia Circuit, because it would have changed the balance of power on the court. Harry Reid, then the Senate majority leader, was compelled in 2013 to use the nuclear option to eliminate the filibuster for non-Supreme Court judicial appointments. This made the elimination of the filibuster for Supreme Court nominations all but inevitable. The way a Republican majority treated Obama’s nomination to replace Scalia ensured that the showdown would happen quickly.