In the weeks leading up to Super Tuesday, Senator Bernie Sanders was the only candidate to win across multiple states. With his more moderate competitors splitting the vote, his success was built on a coalition of union workers, Hispanics and the college-educated.Then South Carolina happened. Now, former Vice President Joseph R. Biden Jr. is banking on a different coalition — this time, of suburban, black and older voters. Is the contest for the Democratic nomination now a two-person race? Guest: Brian Keane, a 52-year-old Democratic voter from Arlington, Va, who spoke with Michael Barbaro about his experiences with Mr. Biden and his thoughts on the 2020 election. For more information on today’s episode, visit nytimes.com/thedaily. Background reading: Here’s what’s at stake in the 14 states (as well as American Samoa and Democrats Abroad) voting on Super Tuesday.Senator Klobuchar and Mr. Buttigieg both dropped out of the race after the South Carolina primary. Can their backing for Mr. Biden help him capture the moderate vote?Mr. Sanders’s strength has complicated the Democratic establishment’s effort to coalesce support around a single candidate.