Each state redistricts differently. In Iowa, two men and a computer are responsible for the process. In some states—like Arizona, Hawaii, Idaho, Indiana, Montana, New Jersey, and Washington—special bi-partisan commissions draw the lines. But in the remaining states, politicians--who are concerned with their own careers--direct the process. Current estimates reveal that one of the two major parties will have unilateral control over the redrawing of 140 congressional districts. The remainder are in states where either both parties have a chance to influence redistricting or where decisions will be made by independent commissions. For a complete look at who draws the lines, visit the Rose Institute.
However, on November 2nd, voters in California and Florida passed legislation that effects how each state draws the lines. In California, the new Citizens Redistricting Commission had its authority expanded with the passage of Proposition 20. The Commission was originally charged with drawing the lines for state legislative districts and Board of Equalization districts (Proposition 11 in 2008), but is now also responsible for drawing congressional district lines. The 14-member commission will be made up of five Democrats, five Republicans, and four commissioners from neither major party. Learn more about the commissioner selection process.
In Florida, Constitutional Amendments 5 and 6 (approved by over 62% of voters) incorporated language into the constitution that limits the power of legislators to draw their districts to guarantee reelection. The amendments prohibit drawing district lines—both congressional and state legislative—to favor or disfavor any incumbent or political party; they require districts to be compact and to utilize existing political and geographical boundaries, while at the same time protecting minority voting rights.
Reforms in both states are designed to limit the scope of political gerrymandering, which allows legislators to pick their voters, rather than the other way around. In a further effort to increase redistricting transparency, researchers have released District Builder—free, open-source web-based software—"that will enable greater public participation and transparency during the upcoming electoral redistricting process."