Is it the Message or the Messenger? Examining Movement in Immigration Beliefs

How do political leaders affect constituents' beliefs? Is it rhetoric, leader identity, or the interaction of the two that matters? Using a large-scale experiment we decompose the relative importance of partisan messages vs leader sources, in the context of beliefs about immigration. Participants listen to anti-immigrant and pro-immigrant speeches from both Presidents Obama and Trump. These treatments are benchmarked to versions of the speeches recorded by an actor to control for message content, and to non-ideological presidential speeches to control for leader priming. Our findings show that political leader sources influence beliefs beyond the content of their messages in a special case: when leaders deliver unanticipated messages to individuals in their own party. This evidence supports the hypothesis that individuals will "follow their leader" to new policy positions