It is fitting that a man who lost so much money in the casino business will meet his final showdown in Las Vegas. At this point — Donald Trump’s third and final televised debate with Hillary Clinton on Wednesday — the odds are stacked against him. Having squandered his near parity with Mrs Clinton in September, Mr Trump has launched a breathtaking electoral blitzkrieg.

Is it the last gamble of an undisciplined narcissist? Or does scorched-earth Mr Trump pose a threat to US democracy?

Anyone concerned about America’s future role in the world should be relieved Mr Trump is the challenger. Imagine the state of the race were he capable of staying on message. Instead of denigrating the women who have made allegations of sexual misconduct against him, Mr Trump would be focusing on his case for “Americanism” versus Mrs Clinton’s “globalism”. He might have a serious chance of winning.