Wisconsin’s electorate deserves a vote of thanks. It is too early to declare that the Republican tide has turned — or that Donald Trump’s weaknesses are finally being exposed. They should always have been obvious. But Mr Trump’s defeat to Ted Cruz offers a glimmer of hope that the electorate may finally be awakening to his flaws.

It would take an improbable series of results in the coming weeks for Mr Cruz to overturn Mr Trump’s delegate lead. Even then, a Cruz nomination would offer Republicans no greater hope of regaining the White House. But Mr Trump is a preposterous candidate. The longer this fissiparous Republican primary goes on, the more voters see what a President Trump would stand for. It is not a pretty sight.

As ever, Mr Trump is happily supplying the evidence himself. In the past fortnight his stream of gaffes has become a torrent. By unfavourably contrasting the looks of his wife, Melania Trump, to those of Heidi Cruz, his opponent’s spouse, Mr Trump provoked women to turn out against him in even greater numbers. It also gave Mr Cruz, no Mr Nice Guy, the chance to humanise his message.