… We saw this during the Republican primaries. Donald Trump led poll after poll, but seasoned political observers simply refused to believe he would win. … And then, of course, he won.
Brexit followed much the same path. Even as the polls tightened, elite sentiment remained confident. On the eve of the vote, polls showed “Leave” even with “Remain,” but betting markets overwhelmingly assumed Britain would stay in. … And then, of course, “Leave” won. CONT.
Ezra Klein, Vox