Joe Biden officially accepted the Democratic presidential nomination Thursday night in a moment that marks the climax of his party’s unorthodox 2020 national convention. The former vice president, who at 77 years old would be the oldest president ever elected becomes the Democrats' official standard bearer for the campaign against President Trump in November. The focus has been on uniting the deeply divided nation as Americans grapple with a health crisis, economic devastation and a national awakening on racial justice. Also on the show, the top Russian opposition leader is in grave condition from a suspected poisoning.