Because proportional representation (PR) elections with preference votes are based on multi-member districts and induce intraparty competition, the literature questions whether incumbents enjoy an advantage in those systems. In this paper, I argue that, like in any other electoral system, incumbents in preferential PR elections are political entrepreneurs: They use their political status to obtain an electoral advantage. But, in multi-member systems, this advantage may reflect strategies that intend to expand political support to other areas in the district. Using data from legislative elections in Brazil at the level of poll ing stations, I identify candidates' geographical hotspots---electoral bases---and test whether incumbents are more successful in maintaining and expanding political support across consecutive contests. Exploiting the fact that preferential PR systems allocate seats differentially to candidates with identical performances, I show that incumbents enjoy an overall advantage and expand electoral bases without losing support in old hotspots. Further, I show that incumbents can use their political status to influence party decisions, channeling resources to their campaigns and avoiding competition from co-partisans. These findings indicate that the literature often underestimates incumbency advantage in preferential PR elections.