Having spent over $500 million on a race only to win American Samoa (and Aspen), Mike Bloomberg is suspending his campaign. He basically spent $50 million for each delegate he won.
Bloomberg is not officially dropping out and none of the others are either. The reason is that as long as they just suspend, their delegates continue to be bound to them and cannot become free agents able to be wooed by Sanders.
This puts Joe Biden on the trajectory to get a majority of delegates and ensure his nomination as the Democratic Party nominee.
Also, turns out that money in politics is not as big a deal as Elizabeth Warren claimed.