The effect of gerrymandering for incumbents is particularly advantageous, as incumbents are far more likely to be reelected under conditions of gerrymandering. For example, in 2002, according to political scientists Norman Ornstein and Thomas Mann, only four challengers were able to defeat incumbent members of the U.S. Congress, the lowest number in modern American history. Incumbents are likely to be of the majority party orchestrating a gerrymander, and incumbents are usually easily renominated in subsequent elections, including incumbents among the minority.