Over the past 30 years, the U.S. states have increased their participation as amici curiae significantly, in addition to winning more of their cases as direct parties. However, little attention has been paid to the factors that cause amici participation rates to vary among the states. The author examines the decision of state attorneys general (AGs) to initiate or join amicus curiae briefs in all 253 U.S. Supreme Court criminal procedure cases from 1990 through 2001. He hypothesizes that AGs are motivated largely by their own policy preferences and by their motivation to get reelected. Because amicus briefs are not particularly high-profile policy tools, reelection motivations ought to be demonstrated through responsiveness to elites in state government. The findings provide less support for this idea and more support for the idea that state AGs follow their own policy preferences through amicus participation.
