When did Clinton become the prohibitive favorite?

[Pouring Rain and Blairing Music]

As others have said, when Biden declined.

There were definitely times when Clinton was vulnerable (especially after New Hampshire), but March 1st and even more so March 15th nailed the coffin for Sanders's campaign. He has ran an impressive campaign in terms of expectations from a year ago, but not quite good enough.

Without a third major player, there was no real hope for him, however.