Republicans are the ones defending maps now because it was the GOP that organized in 2010 to flip state legislatures and control the map-making in several states, Li said. But he noted that Democrats are also guilty of gerrymandering when they get the chances, and likely would have done so in 2010 if they had been in control of those statehouses. The GOP is scrambling, Li said, because of anxieties about what might happen in 2018.