The article presents an analysis of lay political reasoning on the U.K. EU referendum drawing on data from nine focus groups conducted in England in the few weeks preceding the vote. Participants were from across the political spectrum and with varied voting intentions in the upcoming referendum (Remain, Leave, and some undecided). A rhetorical analysis of the data showed that the ideological dilemma of nationalism (between safeguarding national distinctiveness and sovereignty, on the one hand, and valuing international collaboration and exchange, on the other hand) was a key organizing principle in participants' accounts, as was the distinction between reason and bias. Participants intending to vote Leave as well as Remain engaged with both sides of the nationalism dilemma, seeking to present themselves as both open to cosmopolitan values and as concerned about preserving national sovereignty. Further, the liberal distinction between reason and bias in the data often took the form of a distinction between politics (as biased and corrupt) and the economy (as rational), thus depoliticizing the economy as a neutral and postideological sphere. The implications of these findings for contemporary politics are discussed.