Who leads and who follows in Congress? By leveraging the Twitter accounts of U.S. House of Representatives members, we develop a new understanding of House leadership power using natural language processing methods in new ways. Formal theoretic work on congressional leadership suggests a tension in legislative party members' policy stances as they balance coordination and information problems. When their coordination problem is more pressing, the model predicts that legislative members will follow their party leaders' policy positions. When the information problem is more acute, party members coordinate and give their leaders direction for the party's agenda. Specifically, we exploit the network structure of retweets to derive measures of House leadership centrality within each party. We also use Joint Sentiment Topic modeling to quantify the discussion space for House members on Twitter. Our results provide support for the theoretical insights.