In 2012, after Republicans in Wisconsin redrew state legislative districts, Republican candidates captured 61 percent of the assembly seats despite winning only 49 percent of the statewide vote. The disparity led a group of plaintiffs to sue in federal court, alleging that the maps took partisan gerrymandering too far. Last fall a federal court agreed and ordered the Wisconsin state Legislature to redraw the lines, but the state appealed all the way to the U.S. Supreme Court, which will hear the case, Whitford v. Gill, next week. On Sunday, PBS NewsHour Special Correspondent Jeff Greenfield reports on what may be a landmark case affecting the rules for drawing state and congressional district maps nationwide.