Theory in the sociology of religion suggests that a prerequisite for cooperative coalitions among religious groups on political matters is a decline in sectarianism. In analyses of survey data I show that sectarianism has receded for the religious left but not the religious right. Groups that would comprise the religious right are less likely to want the other conservative religious groups to have an influence on public opinion, while groups on the left are less opposed to other liberal groups having influence. It is particularly clear that conservative Protestants are wary of the influence of Catholics. I also conduct exploratory analyses to examine who, among the members of the religious groups who would comprise the religious right, is more sectarian. I find that while demographics are largely nondeterminative, those who are supportive of religiously-based politics are the least sectarian.