Head-shot photos of Joe Biden and Donald Trump

In Thursday’s debate, neither candidate will be trying to introduce themselves to the American electorate. Both are already extremely well-known. Neither is a star debater, so the aim of each will be to clear a relatively low bar, while hoping the other stumbles.

President Biden has been dogged by the criticism that he is too old and lacking the physical robustness and mental acuity required for another term. His priority will be to demonstrate energy and sharpness, and that he can still think on his feet when it matters. His ability to demonstrate that he is up to this task is a huge test of his candidacy. He has reportedly been preparing intensively for the occasion.

Former president Trump, meanwhile, has always been an aggressive debater, but not always to his benefit. His hectoring, belligerent manner in the first Trump-Biden debate in 2020 is generally regarded as having hurt him with undecided voters. He will have been coached going into this debate that he must avoid seeming intemperate and avoid the kind of angry rambling that characterises his political rallies, especially about issues that most voters don’t want to hear about – like his claim the 2020 election was rigged. He will likely open the debate trying his hardest to do as advised. How well he can stick to the plan is a test of whether he has the self-control that even supporters often fear he lacks.

The candidate that does best in the post-debate reviews will likely be the one who succeeds in appearing most ‘normal’, ideally accompanied by a memorable moment or two in which their opponent slips up and lays bare their biggest flaws.