We present the first direct evidence that state-level public opinion on whether a particular Supreme Court nominee should be confirmed affects the roll-call votes of senators. Using national polls and applying recent advances in opinion estimation, we produce state-of-the-art estimates of public support for the confirmation of 10 recent Supreme Court nominees in all 50 states. We find that greater home-state public support does significantly and strikingly increase the probability that a senator will vote to approve a nominee, even controlling for other predictors of roll-call voting. These results establish a systematic and powerful link between constituency opinion and voting on Supreme Court nominees.
That’s from a newly published paper by Jonathan Kastellec, Jeffrey Lax, and Justin Phillips. Public opinion about the nominees matters over and above the overall ideology of a state’s voters, the nominee’s qualifications, and a senator’s party and ideology.
The analysis generates some fun counterfactuals:
Bork received only 42 votes in his favor (given actual opinion on his nomination, we would have predicted 43). If he were as popular as Alito, however, with the state-by-state popularity of Alito, we predict that he would have been confirmed with 54 votes…
…Thomas was more popular a nominee on average than was Bork, and a bit more popular than Alito. Did this make a difference in his confirmation vote? What if he had been as unpopular as Bork? Our prediction, applying Bork’s state-by-state opinion level instead of his own, is that Thomas would have received only 40 votes—a “landslide” vote against confirmation. Public opinion, it seems, was crucial to his successful confirmation.
Kastellec et al. also predict that Harriet Miers would have won only 32 votes.