While I do not dispute the pivotal role played by party leaders in setting and shifting a party position, I argue that the impetus for party shifts sometimes comes from the "bottom-up"--that is, from party members themselves. At times, the party position held by the leadership conflicts with some members' constituency interests. Faced with this conflict, backbench members use the legislative process to signal their intention to defect from the party on policy unless the leadership modifies the party's existing position. Party members' party-splitting votes under constituency pressures, however, do not always lead the party into a new brand. If one party, particularly a majority party, is divided but the other party is united over a policy issue, this issue drives a wedge within the majority party. If this wedge issue continues to split the majority party and unite the minority party, the majority party is likely to shift its policy position to solve its dilemma of party division. To test my theory of party position shifts, I explore three historical cases in which there was position change by one or both parties over immigration, national security, and trade. More specifically, these include: the switch of congressional Republicans from anti- to pro-exclusion on Chinese immigration in the post-Reconstruction period; the shift of congressional Democrats from a party of "guns" and "butter" to a party of only "butter" in the post-Vietnam War era; and Republican and Democratic flip-flopping on China and MFN in the post-Cold War period. My findings suggest that policy change in these cases is driven by the shifting preferences of members as they try to resolve tension between the party and the constituency. Sometimes party rank-and-file members are in the driver's seat in defining the parties' positions. This is as true for foreign policy as it is for domestic policy. My dissertation shows that in a representative democracy, the transition from voters' preferences to lawmakers' votes occurs through the politics of procedural voting strategies in Congress. / text

Post-force congressional rally effects are presented as a new incentive behind presidential decisions to use diversionary behavior. Using all key roll call votes in the House and Senate where the president has taken a position for the years 1948 to 1993, presidents are found to receive sharp decreases in both presidential support and success in Congress shortly after employing aggressive policies abroad. Evidence does suggest that presidents are able to capitalize on higher levels of congressional support for their policy preferences on votes pertaining to foreign or defense matters after uses of force abroad. But, despite these findings, diversionary behavior is found to hinder rather than facilitate troubled presidents' abilities to influence congressional voting behavior.

Abstract not available