How does electoral competition affect the preferences expressed by representatives in their roll-call votes? Literature on representative-constituency relations suggests two contradictory hypotheses on this issue. One hypothesis is that intense electoral competition induces more ideologically extreme behavior on the part of representatives, because competition increases their need for the electoral resources provided by committed activists. The other is that competition provides incentive for more moderate legislative behavior, as a means of gaining marginal votes outside the representative's activist base. Using the measure of liberal policy agreement computed by the Americans for Democratic Action (ADA), this article reports that competition is more frequently a polarizing than a moderating influence on roll-call behavior. The analysis also reveals some peculiar partisan and regional differences that can produce further insight concerning the impact of elections on legislative behavior.