If Donald Trump were to win re-election, how would he do it?

AROUND THIS time four years ago, on October 28th 2016, the then director of the FBI, James Comey, announced the discovery of new emails that might be pertinent to his investigation into Hillary Clinton. Her polling lead in mid-October had been almost as big as Joe Biden’s is now. Twelve days later she was giving a concession speech. Election day is closer than it was when Mr Comey made his intervention—quirks of the calendar mean this year’s falls on November 3rd rather than November 8th, which is when Donald Trump won four years ago. So Mr Trump is running out of time to catch up. Still, that recent precedent has Americans wondering what they might be overlooking this time.

Mr Biden holds a large polling lead: The Economist’s forecast accordingly gives him a comfortable 92% chance of victory. In the 8% of our simulations where the president wins the electoral college, Mr Trump’s route to victory is almost identical to the path he took in 2016. If he wins his adopted home state of Florida, holds states he won handily—including Arizona, Georgia, Iowa, North Carolina and Texas—then Pennsylvania and either Michigan or Wisconsin, both of which he won last time, would put him over the top. Polls suggest that path is unlikely, but polls underestimated Mr Trump’s strength in battleground states four years ago.