On Wednesday afternoon, Kamala Harris stood in front of the vice-presidential residence in Washington DC, and delivered a short but withering attack on her Republican presidential opponent.

Calling Donald Trump “increasingly unhinged and unstable,” she cited critical comments made by John Kelly, Trump’s former White House Chief of Staff, in a New York Times interview.

The vice-president quoted Kelly describing Trump as someone who “certainly falls into the general definition of fascists” and who had spoken approvingly of Hitler several times.

In the home stretch of political campaigns - particularly one as tight and hard-fought as the 2024 presidential race - there is a natural tendency for candidates to turn negative. Attacks tend to be more effective in motivating supporters to head to the polls and disrupting the opposing campaigns.