Legislative cohesion and presidential policy success

Legislative scholars work under the assumption that legislative party cohesion is highly conducive to legislative success. However, in a presidential system such as that of the US, the relationship may be more complex. This article explores the determinants of presidential legislative success with special emphasis on the impact of the cohesion of the legislative parties and of the one special tool the US Constitution gives the president to influence legislation-the veto. Presidential success, I find, is in part dependent on the extent to which the president's legislative preferences coincide with those of Congress and such agreement is higher when the same party controls the House, the Senate and the presidency. As the congressional parties became more internally cohesive and more polarised from the mid-1980s on, presidents confronted with opposition-controlled congresses had increasing difficulty winning legislative victories within the chambers. As a counter, presidents more frequently resorted to veto threats, which they can and do use strategically to move legislation towards their preferred position.