Last night, thousands of people gathered in Chicago for the first night of the Democratic National Convention. And the crowd at the United Center was ready for a party. The evening featured a cameo from their candidate, Vice President Kamala Harris, and speeches from Representative Alexandria Ocasio-Cortez, former Secretary of State Hillary Clinton and, closing out the night, President Biden. Before he could begin his speech, he received a sustained round of applause — more than four minutes long. It was just one memorable moment over the course of an evening that was both a goodbye party and kickoff event. The Run-Up is coming to you from the D.N.C. all week. Today: Night One in Chicago, where the Democrats attempted to reclaim a certain expression of patriotism, and gave thanks to Mr. Biden.