Theories of candidate ideological position-taking draw mixed conclusions about the occurrence of dynamic re-positioning. If audience costs are high, candidates will adopt a static position that appeals to either primary or general election voters. If audience costs are low, candidates can dynamically adjust their positions to align with both constituencies throughout the two-stage election. By analyzing the Facebook posts of candidates in the 2016 U.S. congressional election, I develop a continuous measure of the expressed ideological position of those candidates and evaluate whether the extremity of their positions shifts after a victorious primary contest. Using multiple causal estimators, I find that while all candidates moderate their expressed ideology as the general election nears, those in competitive primaries dynamically adjust their expressed ideology from extreme to moderate immediately after winning a primary election. These results offer evidence in favor of dynamic theories of candidate position-taking.