The American courts have become increasingly central to many important political debates. The marriage equality debate, the boundaries between religious freedom and society, the death penalty, eminent domain and many other contemporary issues that have direct effects on the lives of all Americans continue to play out in the court systems. While Alexander Hamilton in Federalist 82 sees the federal and state courts as complementary, this research sees these courts as often-rival political venues that political interests make strategic choices about taking legal actions in.

Prior research finds that political interests turn to the state courts for two reasons: The structure of law creates a legal incentive and the political interests have access to state level resources, e.g. attorneys skilled in the laws of a state. Yet, there appear to be important gaps in existing theory. A distinction between state and national political interests is seemingly important. State political interests are embedded within their state political communities; consequently these interests should have strong attachments with their respective state courts. Also, state political interests can be expected to select courts on the basis of political ideology and state judicial selection methods. Prior research has shown the connection between these factors and judicial decision-making, but not interest group participation.

To examine these areas of uncertainty, this research collected more than 3500 observations of the participation of political interests in the American courts. Two legal areas were selected: eminent domain and marriage equality. Ultimately, this study finds that state political interests develop strong attachments to their respective state courts and are more likely to enter into the state courts than their nationally-oriented counterparts. This research also finds that judicial ideology and state judicial selection both influence the decision to enter into the state courts. This shows a relationship between these factors and the decision to enter into the state courts. It also suggests that these factors not only affect the choices that judges make, but other actors as well, including political interests.