In The Decline of Supreme Court Deference to the President, Lee Epstein (Wash U.) and Eric Posner (Chicago), submit the prevailing wisdom that presidents enjoy unusually favorable success rates at Supreme Court to data. Obviously, both in terms of case selection as well as benefits from having the Solicitor General's office argue the president's cases, plausible reasons support the conventional wisdom. What Epstein and Posner find, however, is that the conventional wisdom may warrant an updating.
The paper exploits "an original dataset consisting of cases of concern to each of the modern-day presidents (from Franklin D. Roosevelt forward). The modern U.S. Supreme Court Database served as our foundation. This version covers all orally argued cases (including per curiam opinions) decided between the 1946 and 2015 terms. To include the Franklin Roosevelt administration, we appended cases from 1932- 1945 terms using the legacy Supreme Court Database. In total, our dataset covers 13 presidents and 84 Court terms. For all terms, we exclude per curiam decisions.”
The paper's main findings include that the "historical dominance of the president in the Supreme Court reached its apex in the Reagan administration, which won nearly 80% of the cases, and has declined steadily since then. In the Obama administration, the presidency suffered its worst win rate, barely 50%." The authors' explanations for this trend include a "growing self-assertion of the Court and the development of a specialized private Supreme Court bar. We find no evidence for two other possible explanations—that the trend is due to greater executive overreaching than in the past, or ideological disagreements between the Court and the presidency.”