In this book we set out to explore what are the effects of political polarization on supreme and constitutional courts. We investigated this question using a wide variety of comparative examples, looking both at clusters of systems (the US, Europe, British-based systems) as well as specific test cases (India, Brazil, Israel).

We found that the answer depends mainly on three factors: the level of polarization, the political power of the court, and the existing cultural and institutional conditions. Where polarization is high – especially of the affective type, in which opposing camps perceive each other as existential threats; where courts hold great political power, with the ability to shape critical political outcomes, sometimes irreversibly; and where there are no institutional or cultural buffers to mitigate these pressures, then, the case studies in this book suggest, courts themselves become partisan institutions.

This has significant detrimental consequences in four main areas: judicial nominations become partisan battleground, sometimes leading to deadlocks in nominations; judges divide into camps that align, more or less openly, with the rival political factions, and frequently one camp attains dominance within the court; conventions of fairness and etiquette in or around the court lose their hold; and public trust in the court declines, and becomes partisan itself. Courts, therefore, forfeit their traditional legitimacy as neutral arbiters applying objective legal standards and acquire a different and narrower form of legitimacy: they become guardians of the values and interests of one political bloc, thereby enjoying the trust of that bloc while losing, sometimes completely, the confidence of the other.

This however does not happen to the same extent in all countries. The variations that we explored helped us, towards the end of the book, devise context-sensitive tools to protect courts, and the legal system as a whole from the formidable challenges that polarization poses to them and to societies at large.