In a season of discredited predictions, here is a safe one. The presidential debates between Hillary Clinton and Donald Trump will shatter all audience records. Their draw will bear no relation to the substance of the issues. Tens of millions will tune in to watch our age’s most trigger-happy insulter denigrate one of the world’s most famous women.

In ancient Rome gladiators slaughtered barbarians to keep the people entertained. In this case however, the barbarian has a shot at becoming emperor. Whether or not he succeeds, US democracy will never be the same.

What happens in the debates will offer Mr Trump’s best chance of gaining the prize. By any normal measure, Mrs Clinton’s campaign is light years ahead of her rival. Her fundraising machine is running at full pelt, raising close to $300m so far — nearly five times Mr Trump’s total. Her voter registration operation is pounding the streets in the key swing states. Mr Trump does not yet have a ground game worth the name. Mrs Clinton’s Brooklyn headquarters is the size of a small corporation with hundreds of full-time staff. Mr Trump’s Manhattan operation consists of a small circle of loyalists with scant electoral experience among them.