Executive opportunism, presidential signing statements, and the separation of powers

Executive discretion over policy outcomes is an inevitable feature of our political system. However, in recent years, the President has sought to expand his discretion using a variety of controversial and legally questionable tactics. Through a series of simple separation of powers models, we study one such tactic, employed by both Democratic and Republican presidents: the use of signing statements, which purport to have status in the interpretation of statutory meaning. Our models also show that signing statements upset the constitutional vision of lawmaking and, in a wide range of cases, exacerbate legislative gridlock. We argue that courts should not legally credit signing statements; we conclude by discussing executive opportunism broadly.