W hat happens to a political leader who is too sure of themself? Sometimes, huge confidence is a very useful, self-fulfilling quality: persuading party colleagues, activists, donors and voters that more can be achieved than is usually thought possible. Such utter conviction can keep everyone believing while the actual practicalities of a political project are worked out.

Yet when an air of absolute certainty turns out to be overconfidence, the bubble bursts. The politician may be revealed as disastrously complacent and lacking in judgment, having delusions of grandeur, or being fundamentally in denial. Especially in our era of online mockery and instinctive contempt for politicians, an overconfident leader can end up as a laughing stock.

This week is the second anniversary of the start of Kemi Badenoch’s Conservative leadership. So far, self-assuredness has been her tenure’s central feature, the one aspect that many voters and journalists have noticed.…