Hillary Clinton has been putting herself forward as the carefully reasoned candidate, behaving in calm contrast to the shoot-from-the-hip (and often shoot-in-the-foot) emotionalism of Donald Trump. Clinton’s camp is convinced this strategy will win her the election. But it may actually be the thing that loses it for her.

With the debates approaching, it’s worth remembering the last presidential hopeful who defined himself as the candidate of Spock-like rationality: Michael Dukakis. As the governor of Massachusetts, Dukakis prided himself on his technocratic bona fides. “This election is not about ideology,” Dukakis said at the Democratic convention in the summer of 1988, “it’s about competence.” None of this passion nonsense for Mike. It was, with him, a point of pride—the sort that comes before a fall.