But it is in the area of judges that the norms have been shredded the most. In an extended era of closely divided Senates and sharply polarized and tribalized politics, judgeships have taken on heightened importance. Congressional majorities and presidential terms are transitory; judges are there for decades after the presidents who nominated them and the Senate majorities who confirmed them are gone. And as the political process has become more sharply partisan, judicial dynamics have as well—on many significant and controversial cases the Supreme Court divides 5–4, and the votes of both the five and the four are almost always predictable, based on whether the president who nominated them was a Republican or a Democrat.

With Congress paralyzed by divided politics and few opportunities to pass major bills, many important areas of policy are now shaped significantly by judges. And whether it is questions involving corporate and union power, workers’ rights more generally, voting rights, campaign finance, the rights and roles of women, or the nature and limits of executive power and regulations, policy outcomes now depend on which judges are involved far more often than in the past. And the political parties, especially but not only the Republicans, are far more careful than in the past to make sure that the judges their presidents nominate will not deviate significantly from orthodoxy. Nowhere was this more overt than when Trump pledged that any nominee he would choose for the Supreme Court would have to first pass muster with the Federalist Society.

In 2005 and 2006, Democrats filibustered a number of extremely conservative Bush nominees for appeals courts, leading to a threat by then–Majority Leader Bill Frist to blow up the filibuster rule for these judges; a bipartisan “Gang of 14” averted that action with a compromise. McConnell used the filibuster much more broadly when Obama was president, to delay or block many judges just to keep the slots open for the next GOP president. He took the tactic to a new and unprecedented level when he told then–Majority Leader Harry Reid that he and his Republican colleagues would use the filibuster to block any nominees for the three vacancies on the most important lower court, the D.C. Circuit, which hears the cases involving executive power and separation of powers, no matter their qualifications or moderation in views. His goal was to preserve a conservative majority on the court at any cost.

Reid then took the step that Frist had threatened, lowering the threshold for cloture on lower-court and executive nominations from 60 to 50. Reid was harshly criticized by many pundits and journalists for his action, but if he had not done so, the D.C. Circuit would have hamstrung Obama through much of his presidency, and the vacancies would have been filled by Trump, cementing a conservative majority for decades to come. It then became predictable that McConnell, now leading the Senate majority, would extend the change to the Supreme Court. But anybody who had watched McConnell over the years knew that McConnell would have done so even if Reid had not acted first.