This chapter engages with issues concerning religious establishment. The principle of justificatory neutrality entails limitations on the material and symbolic acts of support that the political order may make with respect to religious beliefs or institutions. Violations of justificatory neutrality signal to citizens that the values embedded in the political order may be at odds with their own value commitments and beliefs and may generate feelings of insult or exclusion in certain citizens. Therefore, justificatory stability requires that the government avoid express or implied endorsement of religious premises. This chapter examines U.S. case law on government involvement with religion to develop principles and parameters consonant with the end of political stability.