Gerrymandering has a long and unpopular history in the United States. It is the main reason that the country ranked 55th of 158 nations — last among Western democracies — in a 2017 index of voting fairness run by the Electoral Integrity Project, an academic collaboration between the University of Sydney, Australia, and Harvard University’s John F. Kennedy School of Government in Cambridge, Massachusetts. Although gerrymandering played no part in the tumultuous 2016 presidential election, it seems to have influenced who won seats in the US House of Representatives that year.
“Even if gerrymandering affected just 5 seats out of 435, that’s often enough to sway crucial votes,” Mattingly says.
The courts intervene when gerrymandering is driven by race. Last month, for example, the Supreme Court upheld a verdict that two North Carolina districts were drawn with racial composition in mind (see ‘Battleground state’). But the courts have been much less keen to weigh in on partisan gerrymandering — when one political party is favoured over another. One reason is that there has never been a clear and reliable metric to determine when this type of gerrymandering crosses the line from acceptable politicking to a violation of the US Constitution.
[ed. See: The Mathematicians Who Want to Save Democracy]
