Who draws the lines?
Redistricting status map
|DOJ only||AK, AZ, CA, MS, NH, SD|
|DOJ and court||AL, FL, GA, LA, NC, NY, SC, VA|
|Court only||MI, TX|
Section 5 of the Voting Rights Act is a special provision, covering only some jurisdictions. It applies where a "test or device" was used to screen would-be voters, and where fewer than half of the eligible voters either registered or voted in 1964, 1968, or 1972. Much of the limited political participation in these areas was caused by the disenfranchisement of minority voters.
Nine states, and parts of seven others, are "covered jurisdictions" under section 5. Coverage is not eternal: in a procedure known as "bailout," after ten years of steps to improve opportunities for minority voting, a covered jurisdiction can ask the federal trial court in Washington, D.C. to be released from Section 5. The U.S. Department of Justice keeps a list of jurisdictions that have bailed out so far.
In any jurisdiction covered by section 5, the government may not implement any change to any voting procedure -- including a redistricting plan -- without first submitting the change to the Department of Justice or the federal court in Washington, D.C. This is known as the requirement of "preclearance."
New district lines will usually be precleared 1) if the plan is not intended to dilute minority votes, and 2) if it does not cause "retrogression" in minority political opportunity, intended or not. A new plan will cause retrogression if it presents a diminished opportunity for minorities to elect their candidates of choice, as compared to the existing district map. In order to assess retrogression, the Department of Justice will look at minority political opportunity given the most recent information from the 2010 Census, and will compare that opportunity under the existing district map (the "baseline") to the proposed redistricting plan.
If a jurisdiction covered by section 5 cannot prove that minority voters will be no worse off under the proposed plan, then the Department of Justice will object to the plan, and it cannot legally take effect.
Additional preclearance resources
Tearing Down Obstacles -- A Guide to Section 5