Kamala Harris has proved herself qualified to lead the free world

Kamala Harris may not be the strongest candidate that the Democratic Party could have mustered if Joe Biden had given in sooner to the realities of biology. It was a missed opportunity for American democracy that a wider field could not have been tested in a full set of primary elections.

Ms Harris, after all, proved to be a weak candidate when she ran for the presidency in the primaries four years ago. She has no great record as vice-president, having been handed responsibility for immigration policy by Mr Biden, which has not been one of his administration’s successes.

She is, as she confirmed on Thursday night, a merely adequate public speaker – easily outshone by the stars who preceded her: Barack and Michelle Obama, Bill Clinton and her own running mate, Tim Walz.

However, she possesses important strengths. The most significant, perhaps, was demonstrated simply by winning the nomination. One does not become a major-party candidate for the US presidency in a competitive election by accident. As Lyndon B Johnson and Mr Biden have shown, the vice-presidency is a tried and tested route to the top, requiring a different set of political skills from those needed to win primary elections.

Ms Harris has done more, too, than merely allowing the nomination to fall into her lap when Mr Biden stumbled. There was a brief moment when the Democratic Party considered the possibility of other candidates, but she acted with some ruthlessness behind the scenes to secure her position, and the team that she assembled delivered a national convention of unprecedented unity and optimism.

This set the scene for the vice-president’s address on Thursday night. As The Independent’s Mary Dejevsky commented, the speech was “business-like,