Donald Trump realised he had backed a loser on Friday. At a rally to support Luther Strange, his chosen candidate for the senate seat in Alabama, he hemmed and he hawed.

After setting up his man as the underdog, leaving room for a punchline that would surely have Mr Trump emerging as his saviour, the president took an odd tack.

"And I might have made a mistake. And I'll be honest, I might have made a mistake," he said, in a rare moment of doubt.

And so it turned out. As the results rolled in on Tuesday night, they showed that Mr Trump’s “Big Luther” had lost to Roy Moore, an arch-conservative judge.