For present purposes, I take “America’s Unwritten Constitution” to refer (at least in some measure) to the norms, conventions, and practices that have developed in America to give meaning to, and fill in the gaps of, the constitutional text that was penned in 1787, ratified by a requisite number of states shortly thereafter, and formally amended by the Bill of Rights in 1791 and seventeen times during the two-and-a-quarter centuries since. One important constraint on the nation’s Unwritten Constitution is that is must, at some acceptable level, accommodate itself to the written document. A related feature of the Unwritten Constitution is that, as with the formal text, abiding aspects of the unwritten version need to be anchored in some kind of political foundation. These two features of the Unwritten Constitution – a fidelity to the document itself and a grounding in democratic processes – can be helpfully appreciated by examining another crucial component of today’s Unwritten Constitution, and one as to which federal courts have generally been much less central in determining the meaning and operation of the written Constitution’s provisions: the way we select Presidents in America.

This chapter engages in a comparative examination of cause lawyering in the prisoners’ rights and animal rights movements. Drawing on the rich literature on cause lawyering and social movements, and on American constitutional law, it discusses the similarities and differences in the possibilities for legal advocacy concerning the rights of incarcerated persons and the treatment of non-human animals. The chapter offers a descriptive account of three areas in which these movements might be studied through a comparative lens – countering invisibility; facilitating moral suasion; and overcoming disenfranchisement. The chapter suggests that these comparisons might lead public interest lawyers working in these respective spaces to share ideas about strategic approaches and potential similarities that might be employed to overcome common barriers to progress. It also explains that this typological model for comparing cause lawyering might be employed by scholars in examining relationships between and among other social movements.