Biden will enter because:
- DNC goal is to choose a candidate who will win in the general election. 
- Sanders may turn out to be more popular than Hillary in Democratic population but less popular in total population.
- Biden may be less popular in Democratic population but more popular in total population. 
- If they don’t put Biden in, and Sanders edges out Hillary, DNC risks losing the general election.
- Despite the press saying “Hillary Won!”, Google Analytics and Godaddy online polls show much stronger response for Bernie.
Nate Silver: “The Media Underestimated Hillary Clinton, But Overestimated Her Debate ” I knew it, the online polls showed it, but you won’t read it in the NY Times. 
Hillary wants him now as a straw man, she is feeling lucky and wants a little professional wrestling action before the clincher.  Based on endorsements, 538 is giving it to her by a landslide, so she can afford to be generous.