Mobilizing the Public Against the President: Congress and the Political Costs of Unilateral Action

Prior scholarship overlooks the capacity of other actors to raise the political costs of unilateral action by turning public opinion against the president. Through a series of five experiments embedded in nationally representative surveys, we demonstrate Congress's ability to erode support for unilateral actions by raising both constitutional and policy‐based objections to the exercise of unilateral power. Congressional challenges to the unilateral president diminish support for executive action across a range of policy areas in both the foreign and domestic realm and are particularly influential when they explicitly argue that presidents are treading on congressional prerogatives. We also find evidence that constitutional challenges are more effective when levied by members of Congress than by other actors. The results resolve a debate in the literature and suggest a mechanism through which Congress might exercise a constraint on the president, even when it is unable to check him legislatively.