The central claim of this dissertation is that organized business’s rise to political power and its variable relationship with the Republican Party are tightly linked. Indeed, I argue that business’s political renaissance in the late twentieth century is tied to an increasing reassertion of power within the Republican coalition. Whereas analysts of business power typically highlight the organizational tools developed by business groups to assure unity within an otherwise diverse array of interests and pursue their political comeback, I will show that attention to the relationship between business and the GOP enables us to situate these tools — business’s deployment of PACs, for example, or their increasing attention to elite-level lobbying — in a larger partisan political context. As we will see, and in contrast to existing scholarship, business’s relationship with the conservative movement of the postwar period and the Republican establishment varied over time. Careful attention to the reasons underlying that variability make clear that business’s central place within the Republican Party has never been guaranteed, but rather is the result of hard effort and creative defense.