Constitutional courts are often concerned with asserting their own legitimacy against claims of undemocratic usurpation. Different courts respond to these issues in different ways. In particular, some constitutional courts (on an American model) attempt to assert a sharp distinction between law and politics and insist that their legitimacy is secured by remaining solely on the legal side of the divide. In contrast, other constitutional courts assert their role as guardians of political principles as a legitimating basis for their authority (Germany, India). This paper examines constitutional courts in Austria, Hungary, and Israel as cases of the deployment of legitimating claims based on legal or political authority and considers the consequences of these different approaches for public trust in constitutional institutions.