How do U.S. Supreme Court justices decide how to vote in cases? I would suggest that for all of the complex legal, strategic, and attitudinal models set forth by scholars, a reasonable response to this question would be to ask another, very simple, question - How do you make important decisions?
Of course, the approaches noted above have provided very useful insights on how members of SCOTUS decide how to vote and the plentiful scholarship on this topic has led us to be able to explain a lot of the justices' voting behavior. However, I sometimes think that we get a bit too far from the notion that justices are human decision makers and that their actions can be considered in this light. A related question that has caught both academic and media attention has been the idea of justice drift over time - do justices' jurisprudential views (as revealed in their voting) change over time? Recent research by Andrew Martin, Kevin Quinn, and Lee Epstein suggests that they do in fact drift. Why? Again, I might ask you the same question - have you ever changed your views on a topic? Do you know a friend who has done so? If so, then why did you or they change views? Larry Baum suggests that we consider judges as very human decision makers who are very concerned with their "audiences" and are, accordingly, influenced by the concerns that inform their daily lives. Consider the following quote by Justice William Rehnquist on justice behavior:
The judges of any court of last resort, such as the Supreme Court of the United States, work in an insulated atmosphere in their courthouse where they sit on the bench hearing oral arguments or sit in their chambers writing opinions. But these same judges go home at night and read the newspapers or watch the evening news on television; they talk to their family and friends about current events. . . Judges, so long as they are normal human beings, can no more escape being influenced by public opinion in the long run than people working at other jobs. And if a judge on coming to the bench were to decide to hermetically seal himself off from all manifestations of public opinion, he would accomplish very little; he would not be influenced by current public opinion, but instead by the state of public opinion at the time that he came onto the bench. (Rehnquist 1986, 20 Suffolk LR 768)
In a recent paper, my co-authors (Brian Levey and Justin Moeller) and I examine justice voting and consider some of the concerns that might influence justices' decision making. We specifically examine what we term "micro publics" - specific audiences which justices may turn to in formulating their self identity and self esteem. In other words, these are the points of reference that may inform justices' world views and color the lens through which they perceive the stimuli involved in the cases that come before them (e.g. case facts, litigants, statutes, Constitutional provisions, case precedent, etc.) - indeed, these are "the times" in which the justices live. The paper "For the Times They Are A Changin: Explaining U.S. Supreme Court Justices' Voting By Identifying Their Relevant Audiences," is available on SSRN.