The origin of the term "gerrymander" is a redistricting law passed by the Massachussets legislature in 1810 and signed by Elbridge Garry whose purpose was to rescue the ruling Democrat-Republican majority from a widely predicted take over of the state government by the Federalists in the 1812 election owing to shifts in voter sentiment. As a result of Gerrymander law, the Democrat-Republicans won more than 70% of the state legislature in spite of getting only 50.8% of the popular vote.
Gerrymandering consists of "packing" and "cracking". Packing consists of packing together some of the opposition votes into a small number of districts in order to make then redundant. Cracking consists of diffusing the remaining opposition votes over many districts so that it will always be accompanied by a majority of your own party. By combining these 2 techniques, gerrymandering decisively foils democratic will.
It is mathematically possible, and judging from Elbridge's Gerrymander not all that uncommon, for Gerrmandering to allow a party with only 50% of the vote to win 75% of the representation. The more votes there are against you, the more constrained this becomes, but it can routinely deliver you a majority even when most voters oppose you.
Proofiness: The Dark Arts of Mathematical Deception - Charles Seife - Google Books
According to the 14th Amendment:
Much like the poll tax, gerrymandering has been used to racist effect. It was commonly employed in the racist south, and elsewhere in the country, to nullify minority voting power. This is now illegal, thanks toAll persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside. No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any State deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.And the Supreme Court has specifically stated that Gerrymandering for racial reasons is unconstitutionlthe Voting Rights Act of 1965, additional federal enforcement and protections of suffrage for all citizens were enacted. Gerrymandering for the purpose of reducing the political influence of a racial or ethnic minority group was prohibited. Poll taxes for federal elections were prohibited by ratification of the Twenty-fourth Amendment in 1964, and a later Supreme Court case struck down poll taxes as a prerequisite for any election. Gerrymandering for political gain has remained possible under the Constitution.
http://en.wikipedia.org/wiki/Gerrymander#United_StatesAfter the Voting Rights Act of 1965 was passed, some states created "majority-minority" districts. This practice, also called "affirmative gerrymandering", was supposed to redress historic discrimination and ensure that ethnic minorities would gain some seats in government. Since the 1990s, however, gerrymandering based solely on racial data has been ruled unconstitutional by the United States Supreme Court under the Fourteenth Amendment, first in Shaw v. Reno (1993) and subsequently in Miller v. Johnson (1995).
However, gerrymandering for partisan gain, as in discriminating against people on the basis of political affiliation rather than race per say, has remained legal. In spite of this clear double-standard, and the fact that gerrymandering clearly destroys democracy, both parties continue to get away with it. As recently as 2006, the Supreme Court ruled again, on a 7 to 2 vote, that effectively disenfranchising US citizens by enabling 50-50 votes to go 25-75, was perfectly legal.
Gerrymandering is everywhere in the US. It is practiced by both parties and has been for more than 100 years.
Is Gerrymander unconstitutional? And if so, how harshly should we criticize our judges for denying this?