Biden shows his knowledge but stumbles over words at news conference

President Biden, in a pivotal news conference designed to save his candidacy, showed moments of fluency and command of detail as he parried questions from journalists, but he also stumbled over words, conflated names and at times gave meandering answers. The result was a mixed performance in a much-anticipated event that many Democrats had been anxiously awaiting to see if Biden could allay their fears about his age, mental agility and ability to defeat Republican Donald Trump.