Just ideology? A study finds another predictor of Supreme Court decisions

To their surprise, they found that experienced lawyers obtained measurably better results at the Supreme Court than ones making their debuts.

“From a political science perspective, people have been wedded to the idea that it’s ideology all the way down,” said Michael J. Nelson, one of the study’s authors and a political scientist at Penn State. “But having an attorney who has argued at least one case before makes you both much more likely to win the case and to attract a particular justice’s vote.”

The differences were substantial, said Lee Epstein, a law professor and political scientist at Washington University in St. Louis and the study’s other author. “An experienced attorney, relative to a novice, increases the likelihood of winning a case by 14 percentage points,” she said. “An experienced attorney, relative to a novice, increases the likelihood of capturing a justice’s vote by 11 percentage points.”