Do members of parliament (MPs) transform campaign promises into subsequent actions once in office? While previous research often finds congruence between election pledges and policymaking activities in legislatures at the political party level, we know less about this relationship at the individual MP level. By assembling novel data on issue emphasis in Japanese candidate manifestos and legislative positions, we study whether campaign communication is a meaningful signal of legislative activities. Based on human coding and state-of-the-art transformer-based transfer learning, we identify policy areas in over 46,000 sentences from 1,259 candidate manifestos published during five election campaigns, covering almost all MPs of the largest government party. We find that a higher emphasis on a particular issue increases the probability of taking a legislative leadership post in the same policy area. This relationship exists across elections, different types of posts, and when controlling for previous legislative leadership positions. We also find more substantial congruence for distributive and public goods posts than for high-policy posts. Our findings suggest that campaign promises provide meaningful signals of legislative priorities and that candidates can gain leadership posts by strategically emphasizing policy areas in their campaigns.