Powerful political actors -- most notably the majority party leadership and president, but also committee chairmen -- not only can sway how rank-and-file members vote, but they can also influence what subjects are brought up for consideration and, perhaps more importantly, ensure undesired legislation never makes it to the floor. This latter practice -- negative agenda control -- is particularly powerful because when something doesn't happen, no evidence of it is left behind for observers, electoral challengers, or voters to attract scrutiny.

Agenda-setting also provides positive power, allowing leaders to set the party's legislative priorities. When party leaders clash over these priorities, the resulting agenda is a window into where power actually lies. By this measure, GOP legislative power mostly lies in Congress right now.  Republican leaders have almost completely ignored the policy priorities of President Trump.

To date, not one major piece of legislation has been taken up that ideologically reflects Trumpism rather than Republican orthodoxy.