It's only been a week since Super Tuesday, but the shape of the 2020 Democratic presidential race has been radically altered.Former Vice President Joe Biden has surged into the delegate lead over Vermont Sen. Bernie Sanders, boosted by an avalanche of endorsements from his former rivals including Pete Buttigieg, Amy Klobuchar, Kamala Harris and Cory Booker.

Sanders has spent the week on defense, insisting that he remains very much a relevant player in the race.

Today, aka "Super Tuesday II." All told, six states -- Idaho, Michigan, Mississippi, Missouri, North Dakota and Washington -- will cast ballots.

The big prize is Michigan, with 125 delegates at stake; both Biden and Sanders have spent time in the state, and Sanders has made it clear that he needs the state.