David Souter killed the filibuster

Now imagine a counterfactual without this epic blunder. Had Souter simply voted like a typical Republican appointee — not in lock step with Antonin Scalia, but as an institutionalist, incrementalist conservative, in line with the current chief justice, John Roberts — then it’s likely that Roe v. Wade would have been mostly overturned in the 1990s, returning much of abortion law to the states, and that the gay rights movement would have subsequently advanced through referendums and legislation rather than a sweeping constitutionalization of cultural debate.

This, in turn, would have dramatically lowered the stakes of judicial politics for many Republican voters, making an untimely event like Scalia’s death less of a crisis moment, a response like the Garland pocket veto less of a necessity and the candidacy of Donald Trump something more easily rejected.

Indeed, I strongly suspect that in a world without the Souter own goal — a world where the Supreme Court had sided with cultural conservatives to the extent one would have expected given the number of recent Republican appointees — a nominee like Merrick Garland could still have been confirmed with Republican votes, and the filibuster could still persist, reserved for the unqualified, corrupt and genuinely extreme. Oh, and into the bargain, Donald Trump might well not be president.