President Biden's decision to step aside from the race came as a shock to many Americans, including some of his own campaign and White House staff. Even after the disastrous CNN debate against former President Donald Trump and the growing calls from Democrats for him to pass the torch, Biden seemed dug in. So, the question is, what finally changed his mind? Over the next hour, CNN's Pamela Brown examines the rise and fall of candidate Joe Biden from his motivations for running against Donald Trump to the final days and hours before his history-making decision.