Each state has its own standards for creating reapportionment plans. In the states where the legislature is in charge of reapportionment, the possibility of gerrymandering often makes the process politically contentious, especially when the two houses of the legislature, or the legislature and the governor, are of different parties. The federal court system is often involved in resolving disputes over reapportionment plans.
The reapportionment cases, heard by the court when Earl Warren was the chief justice, are among the court's most widely accepted decisions on civil rights and equal representation.
The result of reapportionment was that New Jersey went from being represented mostly by Republicans to a majority of Democrats, said a law review article coauthored by Nathaniel Persily, a University of Pennsylvania law professor.
The proportion of Democratic seats in the Senate increased to 58.6 percent from 28.6 percent, and in the New Jersey House to 65 percent from 46.7 percent, according to the article.
Reapportionment is the reallocation of seats in a legislature to the regions from which legislators are elected, following changes in population.
Reapportionment of the United States House of Representatives (the lower house of the U.S. Congress) occurs every year ending in "1", the year after the U.S. Census Bureau performs the decennial census mandated by the U.S. Constitution.
In the states where the legislature is in charge of reapportionment, the possibility of gerrymandering often makes the process politically contentious, especially when the two houses of the legislature, or the legislature and the governor, are of different parties.