How do the transaction costs of office holding affect congressional careers? These costs may influence the kinds of people who select into public office and therefore the representativeness of democratic institutions. Gaining causal leverage on this question has been difficult given that many costs associated with office holding are endogenous to characteristics of legislators. Using a natural experiment, we examine the effect of exogenous changes in transaction costs in the US Congress caused by changes in the availability of direct flights from home districts to Washington, DC. We find that gaining an airport that provides a round-trip direct flight to Washington, DC, is associated with an approximately 1.6 percentage point increase in the probability that a member runs for reelection. One implication of these results is that members more sensitive to office-holding costs — such as moderates or members of underrepresented groups — may be less likely to seek and maintain political careers.