1 Understanding UKIP: Identity, Social Change and the Left Behind ROBERT FORD and MATTHEW GOODWIN **This is a working paper, the final version will appear in a special issue of the journal Political Quarterly** Abstract In this article we explore the structural shifts which help explain the emergence of UKIP as a major radical-right political force in Britain. There are two distinct, but related, aspects to this story. The first is the changes to Britain’s economic and social structure that have pushed to the margins a class of voters who we describe as the ‘left behind’: older, working- class, white voters with few educational qualifications. The second is long-term generational changes in the values that guide British society and shape the outlook of voters. These value shifts have also left older white working-class voters behind, as a worldview which was once seen as mainstream has become regarded as parochial and intolerant by the younger, university-educated, more socially liberal elites who define the political consensus of twenty-first-century Britain. We then move to consider the political changes that have further marginalised these voters, as first Labour and then the Conservatives focused their energies on recruiting and retaining support from middle-class, moderate swing voters. Finally, we show how UKIP has developed into an effective electoral machine which looks to win and retain the loyalties of these voters. Finally, we discuss the long-term implications of this revolt, which has the potential to change the nature of party competition in the 2015 election and beyond.