Past presidential elections have often seen public sentiment shift in response to a major ad campaign, a change of position from a major candidate, unexpected developments abroad, or an economic downturn, but sometimes small moments can prove pivotal.
President George H. W. Bush in 1992, famously checked his watch during a presidential debate against Bill Clinton and Ross Perot. Commenters said that "glancing at the wrist watch in a debate is not considered to be a good move as it often signifies that the person is bored of the discussion."
Former Vice President Al Gore, eight years later, awkwardly approached George W. Bush during a 2000 debate, earning a polite nod of acknowledgement from the Republican and laughs from the audience.
President Gerald Ford, for his part, slipped while climbing down the steps from an airplane in 1975, in a discernably more serious tumble than that of President Joe Biden last year.