What is gerrymandering and how is it used?

Every 10 years with the new U.S. Census, state legislatures set about drawing the boundaries of electoral districts in their states. The majority party in the legislature typically exerts its influence to draw districts that are favorable to itself. For instance, Republicans may observe that Democrats in their state are packed into a few urban pockets, and consequently, they will try to district them into as few groups as possible to give more representation to their Republican voters. Both major political parties are guilty of partisan gerrymandering, but the GOP spends far more money on the practice and often aims to disenfranchise minority voices.

The origin of the term "gerrymandering" is actually one of my favorite historical tidbits. Elbridge Gerry, then governor of Massachusetts, passed a law in 1812 that consolidated the Federalists into a handful of districts and gave disproportionate voice to the Democratic-Republicans. A political cartoon noted the districts' resemblance of a salamander (see picture below), and called it the "gerry-mander." 

Many agree that partisan gerrymandering is a distasteful aspect of our democracy. This year, there have been a flurry of court rulings, including before the U.S. Supreme Court, examining the constitutionality of different voting maps that appear to be designed to disenfranchise minorities. The New York Times has done some excellent coverage that I highly recommend.