In the wake of the government shutdown, a slew of pundits have identified gerrymandering as a cause for the legislative discord.  Gerrymandering refers to the practice of manipulating the boundaries of political districts to grant one party or political candidate an advantage.  The United States has a long history of gerrymandering–the term arose in 1812 after Massachusetts Governor Elbridge Gerry implemented a redistricting plan that obviously benefited his political party.

Gerrymandering works in two ways, referred to as “packing” and “cracking”.  Packing concentrates voters of a single type into one electoral district to minimize their effect in other districts.  Cracking dilutes voting blocs by spreading out voters of a particular type.  In this way, political parties can take advantage of the wasted voter effect–opposition voters are both packed into districts they will already win, boosting their margin of victory and increasing excess votes, and cracked into districts where they are the minority, which wastes votes by increasing votes for the eventual loser.

Article I Section 2 of the Constitution enables gerrymandering.  Members of the US House of Representatives are apportioned among states based on population, at a ratio of one representative for every 30,000 persons.  The Federal Government apportions districts based on populations and the state legislature draws district lines.  This allows state legislatures (or a commission appointed by state legislatures) to draw district lines in ways that favor one political party over another, that affect the influence of minority populations, or that favor incumbent representatives.

Recently, some political analysts have pointed to gerrymandering as the cause of the kind of political polarization that led to the shutdown.  The theory is that gerrymandering has increased the number of ultra-ideological representatives by discouraging competition.  Some point to overwhelming margins of victory as evidence that gerrymandering has stifled competition.

This theory, however, has an obvious flaw—gerrymandering won’t have much of an impact if a state simply isn’t very competitive to begin with.  In fact, drawing competitive districts in some states would actually require gerrymandering.  In Texas, 244 of the state’s 254 counties were won by either President Obama or Mitt Romney by at least 10 points.  176 of Texas’ 254 counties voted for Romney by a more than 40 point margin.  Even if districts were drawn completely independently from any party interests, the result would be a map with plenty of Congressional districts safe for any Republican politician.

Additionally, gerrymandering doesn’t tend to maximize the number of districts where representatives are elected by overwhelming margins.  Instead, gerrymandering attempts to increase the number of districts that are simply safe enough.  If you wanted to gerrymander yourself into office, you would pack many of your opposition voters into already extremely partisan districts, where you would not have won anyway, and then crack the rest of the opposition voters into various other districts.  For example, an area with enough Republican-leaning voters to influence an election in one district could be split into multiple districts, diluting the Republican’s voting power.  The goal is to secure victory with a comfortable, but not overwhelming, margin by guaranteeing that opposition voters are not able to wield enough influence to affect an election.  This can certainly result in the creation of safe districts by diluting opposition votes, but it would not result in overwhelming margins of victory.  Perhaps, then, Congressional gridlock is not symptomatic of a gerrymandered system, but simply a reflection of an already divided country.