 Serving as a congressman was not even considered a career during the nation's first century and a half. Single terms were the norm. But by the mid-20th century, a seat in Congress became a highly sought-after position. Now, nearly all 435 House of Representatives members seek re-election every two years. And most often, they succeed. 80 to 90 percent of House elections are won by incumbents, candidates currently holding office. Even without party support, any candidate that had even moderate success during his or her first term can win 8 to 10 percent more votes in the following election. However, this sophomore surge, as it is called, is much more prevalent in the House than in the Senate. Senators face more obstacles to re-election. Constituents are spread throughout an entire state, rather than just a district, and there is less individual contact with voters, a problem that is heightened by six-year terms. Obstacles or not, incumbents still hold several advantages over new candidates. First, most American voters assume incumbents are going to be re-elected, so they go ahead and vote for them. Incumbents have a natural fundraising advantage as well, since groups are much more likely to back someone with a record of voting in their favor. In the 1997-1998 congressional races, for example, political action committees, or PACS and interest groups donated $158.3 million to incumbents, compared to just $21.4 million to challengers. Along with easier access to funding, incumbents also enjoy more free publicity in the form of press conferences, congressional speeches, the introduction of bills, and junkets in their home districts. Not to mention free postage privileges. Newsletters and information letters can point out achievements, stress policymaking records, and highlight any pork barrel legislation, federal projects, grants and contracts brought into their district. In certain circumstances, incumbents make personal appeals to voters through casework, directly handling an individual constituent's problem. Using political connections to help someone avoid bureaucratic red tape on a personal issue can lead to positive word-of-mouth publicity that a new candidate simply cannot match. Incumbent or not, all congressional candidates must focus their energy on motivated voters. Only 37% of the population vote in midterm or off-year elections. A lot of people don't vote, especially in the primary. Not only am I going to vote, I'm going to run for the U.S. Senate and spend a lot of my money. Karinjiv, Kathuria. February 3rd, 2004. Today, the will of the people is channeled through the 535 people who occupy the seats in the House of Representatives and Senate. Of these congressmen, 435 are representatives in the House, a number that is not fixed by the Constitution. Representatives shall be apportioned among the several states which may be included within this union, according to their respective numbers. The U.S. Constitution, Article 1, Section 2, Clause 3. In 1929, when the number of congressmen in the House had reached 435, Congress decided that number of representatives was large enough. So they fixed the number at 435 seats, and these seats are apportioned or proportionately distributed among the states. Apportionment is reassessed every 10 years to compensate for population shifts. Each congressman in the House represents one of 435 congressional districts for a two-year term. It is very important for them to live in the district he or she will represent and meet constituents' preferred gender, ethnicity, party identification, and political experience qualifications. How a candidate matches voter criteria often determines the relative safety of a district. Historically close districts are called marginal districts, meaning the winner typically wins less than 55% of the vote. In safe districts, the winner gains more than 55% of the vote. Although the number of representatives is not regulated by the Constitution, the number of senators is... The Senate of the United States shall be composed of two senators from each state chosen by the legislature thereof for six years. The U.S. Constitution, Article 1, Section 3, Clause 1. Every two years, one-third of the 100 Senate seats are up for reelection. Running for these seats requires deep pockets. Today's campaigns cost an average of $5 to $7 million. This cost heavily favors incumbents who can gain national campaign exposure while challengers must rely on local and state support. Senators typically receive more national recognition than members of the House as they often debate foreign affairs and ratified treaties. On the contrary, representing an entire state rather than a single district has its trade-offs. Diverse constituencies prevent them from personally interacting with as many constituents as House members, leading to a much less personal connection between senators and their voters. Every one of the 535 seats in Congress is critical to each political party and the balance of power. In the event of a seat opening up, competition becomes fiercely competitive. Each additional seat one can sway the nearly 50-50 split between the parties and whichever party controls the most seats also controls Congress.