Joseph R. Biden Jr.’s plan for winning the presidential election relies on putting together African-American voters of all ages, including younger Black people who are less enthusiastic about him, and white moderates who find President Trump unacceptable. At last week’s Republican National Convention, the Trump campaign appeared to be sowing discord within that coalition. By framing the response to unrest in cities as binary — you are either for violence or for the police — Republicans seemed to be daring Mr. Biden to challenge young Black voters. In a speech in Pittsburgh yesterday, Mr. Biden rejected that choice. Instead, he recognized the grievances of peaceful protesters, while denouncing “the senseless violence of looting and burning and destruction of property.” Today, we examine whether the speech worked — and what it means for the rest of the election campaign. Guest: Alexander Burns, a national political correspondent for The New York Times. For more information on today’s episode, visit nytimes.com/thedaily  Background reading: Over the weekend, protesters and Trump supporters clashed in Portland, resulting in the fatal shooting of a man affiliated with a right-wing group. The shooting immediately reverberated in a presidential campaign now entering its most intense period.In his speech in Pittsburg, Joe Biden deflected Republican criticism and attempted to refocus the spotlight on the president’s character and leadership in the midst of the pandemic.