The constitutionality of a key part of the nation’s Voting Rights Act appeared in serious trouble in the U.S. Supreme Court on Wednesday as the justices heard arguments over Congress’ 2006 reauthorization of the act.

In Shelby County, Alabama v. Holder, the court is asked whether Congress exceeded its authority under the 15th and 14th Amendments when it re-authorized Section 5 under a formula that the challengers contend is outdated and intrusive on state sovereignty. Section 5 currently requires nine states, including Georgia, and parts of seven others to have any changes in their voting practices pre-cleared by the U.S. Department of Justice or the federal district court in Washington, D.C.