In June 2016 more than 70 percent of eligible voters turned out to cast their ballot in the United Kingdom’s referendum on membership in the EU, far above turnout rates usually seen for the UK’s general and European elections. Did voters who would not usually make their way to the ballot box sway the outcome of the Brexit referendum? In his article “Turning out to turn down the EU: the mobilisation of occasional voters and Brexit” published in the Journal of European Public Policy, Lukas Rudolph makes use of the fact that on the day of the referendum heavy rainfall in some of the UK’s regions induced occasional voters to stay at home. Comparing referendum results for regions with higher and lower turnout rates, Lukas shows that voters who would not usually turn out were more likely to vote in favour of Brexit. Drawing on survey data, he shows that occasional voters were not generally favouring Brexit. Instead, empirical evidence suggests that Leave-campaigners were more effective in mobilising occasional voters supportive of Brexit to turn up at the ballot box on referendum day. Drawing on these findings, Lukas concludes “that turnout is critical to understand electoral outcomes and policy choice in democracies, and even more so in single-issue referendums when partisan attachments are weak.”