 Today, a very different Joe Biden showed up at a campaign rally in North Carolina, acknowledging his age, but in a fired-up defense, insisting he can do this job. At his own rally in Virginia today, Donald Trump doubling down on his attacks, taking a victory lap. Tonight, in public, Democrats are rallying behind the president. But in private, there are major questions and concerns about whether their candidate is up for the job. ABC's Rachel Scott leads us off tonight.