Political scientist and pundit Larry Sabato has a warning for Democrats heading into the 2018 midterm elections. He points to 2016 as a “cautionary tale” of being way too overconfident months before an election even takes place.

Press & pundits have now progressed to flat predictions of Dem tsunami in Nov. midterms. Quite possible given Trump…but also premature. Fine to be motivated by good polls, but let 2016 be a cautionary tale. Overconfidence about an election 10 months away can be deadly. — Larry Sabato (@LarrySabato) January 14, 2018

Forget 10 months; overconfidence 10 hours away from an election can be politically deadly. Let’s just ask President Hillary Clinton about that.