To rid the country of partisan gerrymandering, Democrats for years joined with election reformers to take the responsibility for redistricting away from politicians and hand it to independent, nonpartisan commissions. The effort did not begin as an entirely altruistic project; both parties gerrymandered where they could, but Democrats had more to gain by scrapping the practice. They won the argument in a number of places: Voters in states including California, Colorado, Arizona, Michigan, and Virginia have approved redistricting commissions over the past 15 years, protecting more than one in five congressional seats from the threat of extreme gerrymandering.