Democratic presidential candidate Joe Biden left  main rival Bernie Sanders no chance for a dignified exit from a six-state  regional primary yesterday. Sanders' defeat was crushing, especially after a stunning bout against Biden and other major contenders in the March 3 Super Tuesday presidential primaries in Alabama, Arkansas, California, Colorado, Maine, Massachusetts, Minnesota, North Carolina, Oklahoma, Tennessee, Texas, Utah, Vermont, Virginia, and Democrats abroad. Yesterday's pared-down matchup in six states--Michigan, Missouri, Mississippi, Idaho, North Dakota and Washington state--saw Biden reverse Sanders' good fortune.

What happened, and what happens  to Sanders' campaign now? Leid Stories listeners advance their theories.