Michigan is being called a must-win state for Bernie Sanders on Tuesday, which means a new poll from the Detroit Free Press will not be pleasant reading for his campaign. On the eve of the state's primary, the survey has Joe Biden up 24 points in the state, 51 to 27. That suggests Biden is on the brink of taking a huge step toward securing the nomination, but the same Free Press story also takes note of an interesting nugget from modern political history: The last polls before the state's 2016 primary showed Sanders trailing Hillary Clinton by more than 20 points, and yet he scored a stunning upset.
In that earlier election, a higher turnout than expected by young voters was key to Sanders' victory. At the time, political stats guru Nate Silver counted the Michigan upset as "among the greatest polling errors in primary history" at FiveThirtyEight. The question for Sanders is whether history can repeat. Michigan, with 125 delegates, is the biggest prize at stake Tuesday, ahead of Washington (89), Missouri (68), Mississippi (36), Idaho (20), and North Dakota (14). Meanwhile, a new CNN poll has Biden up by double digits nationally over Sanders, 52-36, as the preference of Democratic voters. (Biden scored another endorsement Monday from a former rival.)