The dominant paradigm for policymaking by chief executives is that they are first-movers who change the status quo. I re-evaluate this notion by extending recent advances in measuring the conservatism of policy, and by constructing a new comprehensive measure of presidential action. Though executive unilateralism theories predict whether a given status quo will change, empirical studies rely on aggregate analyses of executive productivity and second-order predictions based on assumptions about the spatial distribution of policies. I fail to find support for unilateral action theory in presidential initiatives at the policy-level from 1992 to 2016. Most of the prediction error is due to a high false-negative rate—with the president acting despite supposed constraints enforced by the Congress. Despite widespread acceptance of unilateral action theory, the results imply either that persistent measurement challenges limit opportunities to assess its empirical implications, that the theory itself over-emphasizes the separation of powers as a constraint on action, or both.