Getting Brexit done? The politics of issue-eclipsing pledges

Leaders are rewarded for delivering on policy pledges. Yet mobilisation strategies often depend on keeping issues and unsolved problems ‘alive’ for electoral purposes. What happens when these incentives collide has been subject to little attention. Drawing on the example of Brexit in the United Kingdom, this article examines the politics of issue-eclipsing pledges – scenarios in which policy pledges directly undercut mobilisation strategies. Brexit offers a good example of these tensions because the referendum vote called the bluff of decades-long Conservative efforts to instrumentalise EU membership for electoral gain. We show how issue-eclipsing pledges produce cyclical and path-dependent dynamics that tend towards radicalisation, as pledges of incumbent elites to guarantee policy delivery are vulnerable to the efforts of non-incumbents to re-interpret pledges and re-mobilise bases of electoral support. We illustrate these dynamics by narrating the interplay of reform pledges and re-mobilisation strategies encountered by successive UK governments since the 2016 referendum.