Evidence on electoral accountability in the U.S. Senate: Are unfaithful agents really punished?

Many have questioned whether voters are able to hold incumbent officials electorally accountable through a retrospective voting strategy. We examine U.S. Senate elections from 1962 to 1990 in forty-one states, explaining which incumbents ran for reelection and their success in seeking reelection. We find that an incumbent's deviation from her state party platform decreases the probability that she will run for reelection and win if she runs. Furthermore, the electoral mechanism is found to be more efficient when voters are better informed. Finally, we find that our divergent party platform model provides a better fit than the median voter model.