We examine the proposition that incentives for legislative organization can be explained by the nature of electoral competition. We argue that legislators in environments where parties are competitive for majority status are most likely to have delegated power to their leadership to constrain individualistic behavior within their party, which will in turn increase the spatial predictability of individual voting patterns. Using roll call votes and district-level electoral data from the U.S. state legislatures, we show empirically that increased statewide interparty competition corresponds to much more predictable voting behavior overall, while legislators from competitive districts have less predictable behavior.