Trump's advisers may have publicly insisted he doesn't need any debate prep, but the former president is preparing more than he's letting on, sources tell ABC News.

Presidential debates are performances. Trump seems easier to trigger into saying something ridiculous and giving himself a self-inflicted wound — than Harris. Harris' big job is to get voters to get to know her better.

Harris will go toe-to-toe with Trump on the ABC News debate stage for the first time amid this year's presidential election.