Final answer:
The high reelection rate for House incumbents since 1950 is between 85 and 100 percent due to the incumbency advantage, which includes factors like name recognition and higher campaign financing.
Step-by-step explanation:
Since 1950, a large majority of all House incumbents running for office have been reelected. The concept, known as the incumbency advantage or incumbency effect, implies that individuals in power have a significantly higher chance of retaining their positions. The data indicates that, for the House, the percentage of incumbents winning reelection has typically been between 85 and 100 percent. This high reelection rate can be attributed to factors such as better name recognition, established voting records, and significantly higher campaign financing capacity in comparison to challengers.
A detailed examination of the data from the Congressional Election Data, 1970-2012, also reveals that African American incumbents have an equally high rate of reelection, with nearly 92 percent being reelected between 1970 and 2012. These incumbents have enjoyed an average margin of victory of 78 percent. The incumbency advantage exhibits itself through various aspects like campaign financing, where, for example, in 2020 Senate incumbents on average raised significantly more than their challengers. This financial edge is a vital component of their continued success in elections.