Retirements also play a factor as some members leave Congress after seeing the new lines for their districts. Rep. Tom Davis, R-Va., head of the National Republican Congressional Committee, predicts 60 to 80 retirements. In 36 of the 43 states that now have more than one House district, control of the governor's office and the legislature determine which party will draw new lines. Each party has full control of the process in seven states. The other states either have split control or use non-partisan commissions to redraw lines.
Plans often wind up in the courts.
Only nine states had plans that weren't challenged last time. The term gerrymandering is a tribute to Elbridge Gerry, a Massachusetts congressman, vice president and governor who, in March 1812, was the first to draw squiggly lines to protect an ally's congressional district. His handiwork looked like a salamander. Other politicians have made notable contributions to the practice. In California, Democratic Rep. Phil Burton, who died in 1983, was considered a master of the craft.