Reapportionment: The allocation of seats in a legislative body (e.g., Congress) among political entities. Seats in Congress are reapportioned among the states at the beginning of each decade according to the relative population of the states. Some states also reapportion state legislative seats at the beginning of each decade among political subdivisions, such as counties. Sometimes, the words reapportionment and redistricting are used interchangeably, but they actually have different meanings.
Redistricting: The designation of the geographical boundaries of the election districts from which members of a legislative body will be elected. For Congress, one member is elected from each such district nationwide. Each district within a state must be equal in population. Only voters within the boundaries of a given district may vote in an election from which the congressman from that district is elected. Therefore, in a politically nonhomogeneous state where voters often are grouped in neighborhoods or communities alongside persons with similar voting tendencies, the location of the boundaries of the district may determine which political party or interest group is likely to win in a particular district. Redistricting occurs for congressional, state legislative, and many local government seats.
One Person, One Vote: The United States Supreme Court has required since the 1960s that election districts must be equal in population. For congressional districts, this means that all districts within a state must essentially be absolutely equal in population, with many states having a difference of only one or two persons among districts (out of a population of over 650,000). The requirement of equality in population is not quite as rigid for state and local government districts.
Neutral Factors: Theoretically, election district boundaries are drawn in furtherance of state policies or interests. For example, congressional district boundaries are likely to follow natural boundaries, like rivers, and political subdivision boundaries, such as county lines or city limits. However, adherence to these neutral factors must yield to the requirement of equal population, so district boundaries seldom are determined solely by these neutral factors (e.g., a county will be split among districts).
Member-Constituent Relations: The recognized, legitimate state interest of drawing the boundaries of districts to maintain the relationship between an incumbent and his or her constituents. The interest is seen as a proper state interest because it maintains continuity for the voters, avoids voter confusion, and, in the case of