A poor performance in a debate against Trump in June was a major catalyst that led to President Joe Biden stepping down and endorsing Harris as the Democratic nominee. And the stakes are high for Tuesday night's debate as well, with poll margins tight in every major battleground state.
George Mason University Professor of Law Francis Buckley emphasized that while both candidates have instinctively played to their loyal bases, their real challenge was winning over the narrow swath of unsure voters who would decide the election outcome.
"The battle is for the 4% of voters who switched from Trump to Harris in the last month," Buckley said.
Economic analyst and former merchant banker Martin Hutchinson said if Harris delivers a clear message and moderate tone she could win the debate, which will boost her election chances.
"Kamala needs to set out a coherent, moderate set of positions with no word-salads and no nonsense like her tax on unrealized gains" Hutchinson said.
Political commentator and former hedge fund manager Charles Ortel underscored the need for Harris to restrain her natural inclination for uplifting but empty rhetoric.
"Kamala has to demonstrate substance and do much more than spewing cliches about progress, opportunity and equity," Ortel said.
TRUMP TEMPERAMENT CHALLENGE
Trump, for his part, also had to resist his own natural inclinations to prevail in the debate, Hutchinson pointed out, while reaching out to the middle class in the suburbs.
"The MAGA crowd are already rooting for him full-tilt; he needs to woo the apolitical and the suburban housewives," Hutchinson said.
Trump's aim is purely defensive and he must maintain a sober demeanor to counter the nonsense that he is "unfit" to be president, Hutchinson said.
"He should avoid being overbearing - as in his first Biden debate of 2020 - and let Kamala mess up on her own time," Hutchinson added. "He did this with Biden in June. He needs to do it with Kamala and hope she messes up."
Ortel agreed that Trump would be best served to show restraint and let the opponent fail on her own, while "simply and quietly" explaining three to five concrete proposals.
"To win, Trump merely needs to let Kamala speak as much as possible," Ortel said.
Buckley said Trump's task is to show that Harris is superficial and a continuation of the Obama-Biden team.
However, Trump needs to do this "without coming across as a bully," Buckley warned.