That said, the assumption that the Court’s agenda is driven (except in a negative sense) almost exclusively by the preferences of its members is clearly flawed. Charles Epp summed up the problem with this claim in his powerful book The Rights Revolution, where he argued that:

Many discussions of the relationship between the Supreme Court and litigants assume that the resources necessary to support litigation are easily generated and that, as a result, litigants of all kinds have always stood ready to bring forward any kind of case that the Court might indicate a willingness to hear or decide. But that presumes a pluralism of litigating interests and an evenness of the litigation playing field that is wholly unjustified. Not every issue is now, nor has been in the past, the subject of extensive litigation in lower courts, due in part to limitations in the availability of resources for legal mobilization.

Litigation is expensive, time consuming, complex, uncertain, and requires a very high level of ongoing organization. Especially where strategic litigation is concerned—litigation that seeks more than a “one-shot” victory in court—success requires the existence of highly motivated, specialized lawyers with a reliable base of funding, who are connected to a broad network of experts in other professions, lawyers willing to be local counsel, academics, and organizations able to provide strategic advice and assistance in identifying clients and cases. Those lawyers must be sufficiently shrewd that they can identify cases with the potential to put their issues in the best light, and to do so (in many cases) repeatedly, in order to generate circuit splits.

Without these sorts of resources, cases that members of the Court would be willing to hear, and would consider sympathetically, will either not reach their door, or will do so in a form that would produce less than the maximum return on the opportunity presented by a particular set of Justices’ preferences.

What is just as important, the litigation piece of the supply-side theory notes that even well-trained justices don’t always know precisely what it is they want, or how far they can legitimately take their own preferences. Usually Justices determine this in part by “feeling around” in the cases that are presented to them. Justices who operate in an environment in which they are constantly being fed well-designed cases that encourage them to consider ever-more-extreme implications of their existing preferences will produce more radical outputs than those who are not given those opportunities.

So, to sum up, the electoral, demand-side, theory of legal change is incomplete in failing to take account of the supply-side constraints on judicial appointments, and on the character of the Court’s agenda. In my third posting, I will identify a final component of the supply-side theory of legal change, which concerns the role of legitimating ideas.