Our objective is to investigate the relationship between presidential campaign activities and political mobilization in the states, with specific focus on the mobilization of core constituents. Using data on presidential campaign visits, presidential campaign media purchases, and party transfers to the states, we highlight some interesting mobilization patterns. First, voter turnout is positively influenced by presidential campaigns, though not by all campaign activities. Second, there is some evidence that campaigns have direct effects on the participation of core partisan groups. Finally, the ability of parties to mobilize their core groups has a strong effect on state electoral success that exists over and above the direct effect of campaign activity on electoral outcomes. All in all, we see the results as strong evidence that political mobilization in general and party transfers to the states in particular are an important component for understanding campaign effects in presidential elections.