Prof. Ryan Rebe has written Analyzing the Link between Dollars and Decisions: A Multi-State Study of Campaign Contributions and Judicial Decision Making. Here is the abstract:
This article examines the causal connection between attorney contributions and judicial decisions in elective states. The results show that contributions are a significant predictor of appellant success in state supreme courts when judges receive contributions from the attorneys for the appellant. However, this relationship is contingent on the competitiveness of the judicial seat. The analysis shows that judges who win landslide victories in the previous election are less likely to vote with contributors during their term than judges who win close elections. This evidence bolsters the argument that contributions directly affect decision making when judges feel electoral pressure. The results also support the proposition that elected judges are more likely to vote with donors in states with nonpartisan ballots. While the contribution amounts are higher in partisan states, the judges in the nonpartisan sample are more closely aligned with their contributors when it comes to decision making.