The incumbency advantage refers to the increased likelihood that incumbents will be reelected. In the House and in the Senate, there is a specific hierarchy of leadership. The Speaker of the House is the most powerful in the House, and the Majority Leader is the most powerful in the Senate. The main work of Congress takes place in committees and subcommittees. A bill begins in a subcommittee or committee, goes to the floor, and, if approved, either goes to the president to sign or to a conference committee to reconcile the differences between the bills. The executive branch has gradually increased in power over time. The judicial branch exercises its power mainly through judicial review. The bureaucracy has also increased in size over time, although the proportion of jobs in the federal government has actually decreased.
Many people criticize Congress for being ineffective and express dissatisfaction with the people in Congress, viewing them as corrupt. However, in spite of this pervasive view, people tend to elect the same representative or senator over and over again. Also, the Framers of the Constitution did not necessarily want Congress to be effective—they wanted there to be significant checks and balances in the process that would keep Congress from amassing too much power.
The incumbency advantage means that incumbents are much more likely to be elected again. In the House of Representatives, 80-90% of the incumbents are reelected, while in the Senate, 70-80% of incumbents are reelected. Here are a few reasons why: