Why are the leaders in some U.S.-style legislatures more influential than others? This study uses individual-level data on lawmakers’ perceptions of their leaders’ influence to test three general theories of legislative power delegation: legislative leaders have no real power, simple collective action theory, and Conditional Party Government theory. These perceptions of speakers’ legislative influence are modeled with varying intercept, multilevel, ordered probit models. The analyses strongly support the simple collective action problem explanation of legislative leadership influence, in particular suggesting that collective problems caused by the internal dynamics of the legislative process drive the delegation of influence to leaders.