What is the effect of a change in geographic location on the behavior of campaign donors? Looking at people who move presents a unique opportunity to assess the ways in which political behavior is altered by external circumstances. Holding the individual constant and observing how donation patterns vary under different external conditions allows us to explore donor behaviors in ways that are more difficult when using cross-sectional data. We use the DIME dataset to compare the donation behavior of over 7,000 individuals in the U.S. House election before and after they have moved. We observe the ways in which changes in the partisanship of the districts that they live in alter the share of their donations that go to each party. We find that the partisan composition of the districts that people arrive in influence their donation behavior – a move to a more Democratic district tends to increase the share of one’s donations that go to Democrats. We conclude by discussing what these findings can tell us about the partisan and strategic motivations of campaign donors.