The last time the Democrats ran a loser again was in 1956.
Stevenson in 1952 and 1956, ran and lost against Ike.
I think Nixon, losing 1960, but winning in 1968, is the only other major parties candidate to run for president again after having lost the general election. In recent history anyway.
It’s as if once you run in the general election, in either party, they are looking for new people, rather than rerun the same old candidates.
Oh, the Bernie people are gonna love this!