“What is our mandate?” he said. “I believe it’s this: Americans have called upon us to marshal the forces of decency, the forces of fairness, to marshal the forces of science and the forces of hope in the great battles of our time.”Senator Kamala Harris, the vice president-elect, spoke first, telling voters that they had chosen “hope and unity, decency, science and, yes, truth.” She invoked her mother, Shyamala Gopalan, who came to the United States from India at the age of 19, and paid tribute to the women “who throughout our nation’s history have paved the way for this moment tonight.” The message, as it was throughout the campaign, was rooted more in a sense of values than in an especially ideological viewpoint, an approach that helped him build a broad coalition throughout the campaign but that will be tested in partisan Washington.Yet Mr. Biden grew impassioned as he insisted that for all of the tensions in the country, Americans still wanted to see their leaders find common ground. He promised to bring steady leadership and experience to meet the staggering crises facing the nation, most prominently the coronavirus. – Advertisement – WILMINGTON, Del. — Joseph R. Biden Jr. addressed the nation for the first time as president-elect on Saturday night, delivering a message of unity and trying to soothe the extraordinary divisions that defined the last four years in American politics.“Let this grim era of demonization in America begin to end here and now,” he said.- Advertisement – – Advertisement – In remarks before a drive-in audience in Wilmington brimming with longtime friends from Delaware, his home state, he directly appealed to the tens of millions of Americans who backed President Trump’s re-election, seeking to make good on his central campaign promise of bringing the country together. “For all those of you who voted for President Trump, I understand the disappointment tonight,” Mr. Biden, speaking at the conclusion of his third run for the presidency, said. “I’ve lost a couple times myself. But now, let’s give each other a chance. It’s time to put away the harsh rhetoric, lower the temperature, see each other again, listen to each other again.”He added, “This is the time to heal in America.”- Advertisement – “While I may be the first woman in this office, I will not be the last,” she said. “Because every little girl watching tonight sees that this is a country of possibilities.” Mr. Biden’s optimistic speech, flecked with references to faith and American history, came 48 years to the day after he was first elected a senator from Delaware. He spoke from a flag-bedecked stage outside the Chase Center on the Riverfront, an event center near the Christina River, where he invoked themes that shaped his presidential campaign.