The ‘Overton window’ is a term from political science meaning the acceptable range of political thought in a culture at a given moment. It was the creation of Joseph Overton, a think-tank intellectual based in Michigan, who died in 2003 at 43 after a solo plane accident. His crucial insight, one which both emerged from and was central to the work of the think tank Right, was that the window of acceptability can be moved. An idea can start far outside the political mainstream – flat taxes, abolish the IRS, more guns in schools, building a beautiful wall and making Mexico pay – but once it has been stated and argued for, framed and restated, it becomes thinkable. It crosses over from the fringe of right-wing think-tankery to journalistic fellow-travellers; then it crosses over to the fringe of electoral politics; then it becomes a thing people start seriously advocating as a possible policy. The window has moved, and rough beasts come slouching through it to be born.
British politics has never seen a purer example of the Overton window than the referendum on membership of the EU.
www.lrb.co.uk/v38/n15/john-lanchester/brexit-blues
