National: The mathematicians who want to save democracy | Nature
Leaning back in his chair, Jonathan Mattingly swings his legs up onto his desk, presses a key on his laptop and changes the results of the 2012 elections in North Carolina. On the screen, flickering lines and dots outline a map of the state’s 13 congressional districts, each of which chooses one person to send to the US House of Representatives. By tweaking the borders of those election districts, but not changing a single vote, Mattingly’s maps show candidates from the Democratic Party winning six, seven or even eight seats in the race. In reality, they won only four — despite earning a majority of votes overall. Mattingly’s election simulations can’t rewrite history, but he hopes they will help to support democracy in the future — in his state and the nation as a whole. The mathematician, at Duke University in Durham, North Carolina, has designed an algorithm that pumps out random alternative versions of the state’s election maps — he’s created more than 24,000 so far — as part of an attempt to quantify the extent and impact of gerrymandering: when voting districts are drawn to favour or disfavour certain candidates or political parties.