How do actors use moral values and moral intuitions together to reason about political attitudes in the United States? Research often shows that public opinion is shaped by automatic, non-rational mental processes—for example, by biases and heuristics stemming from political identity—rather than deliberation. However, this incorrectly assumes that reasoning and automatic processes always conflict. We respond by developing a theory of how actors use moral values to reason about political attitudes in the United States. Key here is the concept from moral psychology of political “Most Sacred Values”—which are moral goals that are central to a moral community and resonate with community members’ moral intuitions. People then reason about politics and form or repeat political attitudes by employing their moral community’s Most Sacred Value. This chapter makes two key contributions. First, we begin to fill the gap in the public opinion literature about how actors use deliberation and automatic mental processes together to reason about political attitudes. Second, by creating a model in which deliberation and intuitions reinforce each other, we open the door to models of public opinion and belief systems in which actors form or repeat attitudes through both reasoning and automatic mental processes.