I have no deep thoughts for you on this but it’s worth asking the question since it’s interesting and I haven’t seen it mentioned elsewhere in all of the post-election counterfactuals. SCOTUS is always an issue for voters in a presidential election but it’s typically background noise: Yes, there’s a chance — almost a sure thing, really — that at least one vacancy will open up in four years’ time, but usually that’s an abstract reality, not a concrete one. Supreme Court appointments under normal circumstances are just one in a basket of issues that makes you a member of the party you belong to. If you’re pro-life, pro-gun, support smaller government, and so on, you vote Republican and simply assume that the president’s Court picks will reflect those priorities.
This year was different for two reasons. One: We’ve had a vacancy on the Court for nine months, and not just any vacancy but a vacancy that imperils the fragile conservative majority. If one of the Democratic justices had died the Court would also be an unusually vibrant, concrete issue this year, but in the end the election would merely have decided how dominant the conservative majority would be. Because it was a conservative justice who died, though — and not just any conservative justice but the conservative justice — the issue of who would replace Scalia was momentous in every sense. Two: One of the major problems with Trump all along to conservative skeptics like me was that you simply couldn’t, and can’t, be sure if he’ll govern conservatively. He’s a protectionist; he won’t touch entitlements; he’s spoken warmly at times about single-payer. All of this was arguably disqualifying. But Trumpers always had a, er, trump card — he’ll appoint a conservative to replace Scalia. He’ll protect that fragile majority on the Court. If for no other reason, Trump is worth backing for that. And that argument was … highly persuasive. Even if, like me, you have no use for the guy and fear he’ll end up as a centrist Democrat as president, there’s really no denying that his SCOTUS picks will be better than Clinton’s would have.
Put those two factors together, the visceral fear Republicans felt of losing their long Supreme Court majority in the first weeks of a Clinton administration and the fact that it created a compelling reason to back Trump despite his many loathsome qualities, and you come to the question in the headline. How many Trump-skeptics bit the bullet in the end and voted for him despite their misgivings, in the name of protecting a conservative Court? How many of them wouldn’t have voted for Trump, or wouldn’t have voted at all, if not for the Scalia vacancy?
We’d need some work from a data site to begin to intelligently estimate that number, but here’s a starting point from the national exit poll:
That’s more than 20 percent of the electorate telling you that this was the most important issue of the election — and Trump won that share of the vote by 15 points. (The 2012 exit poll didn’t even bother to ask about the Supreme Court.) That was worth three points net for him in the overall election. Coincidentally, he and Clinton ended up nearly even in the popular vote even though the final national polling average projected her to win by 3.2 points.
Now, obviously, many people in the “SCOTUS was the most important issue” group who voted for Trump would have voted for him anyway for other unrelated reasons. You can’t count that entire three points as votes that wouldn’t have come his way if not for the Scalia vacancy. What we’re interested in is only the share of that group who wouldn’t have voted for him if not for the prominence of the issue, and there’s no way of telling that reliably. I would point out two circumstantial bits of evidence that it mattered, though. One is that, given how narrow his margins of victory were in Wisconsin, Pennsylvania, and Michigan, with Trump winning the three states by just a bit more than 100,000 votes total, even a small number of #NeverTrumpers coming home to the GOP in the end because of the Court might have been decisive. Trump’s electoral-college margin was impressive but his popular-vote advantage in the winning states was whisker-thin. Every vote mattered. And the Court vacancy surely earned him some reluctant votes.
Two: Trump actually did better with Republicans nationwide than Clinton did with Democrats, which upended months of polling. With a few exceptions, Hillary was at least a couple of points better than he was in consolidating his own side in various surveys this year. But not on Election Day.
Flip those partisan splits, with Clinton at 90/7 and Trump at 89/9, and she’s probably president-elect today. Compare that with these numbers, taken from an NBC/SurveyMonkey poll less than two weeks before the election, asking people whether the Republican Party would unite by Election Day:
Even a majority of Republicans expected the party to be divided. It wasn’t. How come?
One more data point on partisan unity. In all three of the Rust Belt trifecta states, Wisconsin, Pennsylvania, and Michigan, Trump’s support among Republicans was slightly better than Clinton’s was with Democrats. In Pennsylvania the GOP split for him 89/9 (+80) versus Democrats splitting 87/11 for Clinton (+76). In Michigan Republicans broke 90/7 for Trump (+83) compared to Democrats breaking 88/9 for Hillary (+79). And in Wisconsin, which was supposed to be Clinton’s strongest state, they were dead even at +84 in net party support with Republicans dividing 90/6 for Trump and Democrats dividing 91/7 for Clinton. Any degree of underperformance with his own base might have cost him the election, but in the end they were rock solid. Alas, the state exit polls didn’t ask specifically about the Supreme Court, but given how tight those three races were and how remarkable Trump’s support was among what was supposed to be a divided Republican Party, is it likely that the Scalia vacancy made the difference? I think it’s surely possible.