Challengers in U.S. Senate Elections.

The level of competition in House elections has been shown to result primarily from the quality of the challenger. In this paper. I demonstrate that the same dynamic functions in Senate elections. The quality of Senate challengers varies, and the higher the quality of a challenger the more votes he or she receives and the more likely the challenger is to defeat an incumbent. Higher quality challengers are more likely to run in states where the pool of such candidates is large; their appearance in a contest is not due to any personal or political characteristics of the incumbent. Challenger quality matters, in part, because higher levels translate into more campaign money, but quality also indicates other skills that produce additional votes. [ABSTRACT FROM AUTHOR]