This was another of those Faustian agreements made in politics.  Kefauver had been campaigning for the nomination in 1956, and making progress.  The problem that Kefauver had was that he was a goof-ball.  He actually campaigned or at least was photographed as campaigning, and more than once, I might add, in a Davy Crockett coonskin hat!

The professional pols who had run the Democratic Party since the 1920's pulled the plug on Estes but he salvaged the #2 spot.

Estes was also a horrible drunk.  I know first hand a great story.  An old timer local pol went to Kefuaver's funeral and looked at the remains in the casket.  He noted that he had seen ol' Estes in a lot worse shape than that!

Kefauver died on the floor of the U. S. Senate, on on this date in history, in 1963,  after eating some apple pie.

A solid enough pick, much better than Sparkman, but Stevenson did not pick him.  He left the choice to the convention and Kefauver narrowly edged out John Kennedy. 

The one real drawback to Kefauver was his drinking problem.  I don't know if he had it under control by 1956.