The results of Super Tuesday make clear that the race for the Democratic presidential nomination is increasingly a battle between former Vice President Joseph R. Biden Jr. and Senator Bernie Sanders. Today, we explore what happened on the biggest night of the race so far. Guest: Alexander Burns, who covers national politics for The New York Times. For more information on today’s episode, visit nytimes.com/thedaily.

Background reading:

• Mr. Biden is back as front-runner after sweeping states across the south thanks to moderates and African-American voters, while Mr. Sanders harnessed the backing of liberals and young voters to claim California, the biggest delegate prize of the night.
• Primary results are still coming in.Here are the latest updates and The Times’s live analysis.