Recent politics has been characterized by politicians’ harsh anti-immigration appeals and backlash against immigrants. I present a novel explanation for this backlash that hinges on politicians’ ability to make such appeals credible. The starting point is a cheap talk model in which a politician (sender) is aligned with one of two opposed groups (receivers) and seeks to communicate her preferences to win support. Importantly, an increase in the weaker group’s capacity may enable credible communication by the opposed type of politician, ironically making the weaker group worse off. Illustrating the model, I discuss how Donald Trump credibly communicated alignment with anti-immigration groups in 2016 through harsh messaging against immigrants, whose power was increasing. More broadly, the model and case show how the behavior of strategic actors can underpin realignments, with shifts in relative group power proving crucial in enabling politicians to assemble novel political coalitions.