Electoral competition is essential to democracy. Yet the incumbency rate in state-house legislative campaigns is nearly 95 percent. This report examines campaign contribution limits and the impact limits can have on electoral competition. The research on which this report is based was inspired by a 2006 U.S. Supreme Court decision that overturned low contribution limits. The data presented here refutes the Court's assumptions that low contribution limits damage challengers and shows that the lowest contribution limits, those set at $500 or below, enhance challengers' ability to campaign against incumbents in state legislative races. Though public financing systems also increase electoral competition, the Brennan Center's research suggests that incumbents nonetheless continue to opt for public financing systems. Of course, enhanced competition under low limits is only one factor to be considered. Competition, after all, is one key goal in electoral reform, but not the only one. We may wish also to encourage citizen participation and voter engagement. But if we are looking for reasons not to enact low limits, a deleterious impact on competition is not one of them. For this reason, the Supreme Court was wrong in Randall v. Sorrell. Our joint findings make it plain: low contribution limits and public financing substantially narrow the gap between incumbents and challengers. These reforms can be mutually enhancing as reasonable contribution limits are central to a well-functioning public financing system. Incumbency will continue to provide electoral advantages. However, decreasing the vote margins between votes cast for incumbents and their challengers signals greater electoral competiveness and, as such, strengthens democracy.