The system is rigged: Dark money, Citizens United and the secret story of how big money

[merrily]

3. MUCH more recently than a century ago.

In 1952, Kefauver won the primaries. Every primary held at that time, IIRC, but I can't swear to it.

The party bosses were angry with Kefauver because his investigation of "the mob," which had made him so popular with Democratic primary voters, had also revealed connections between the mob and Democratic party bosses (which we heard about again when JFK ran).

The nominee in 1952 was Adlai Stevenson, chosen at the convention by Truman and other party bosses, after Stevenson vacillated like crazy over accepting the nomination. He lost.

In 1968, Humphrey entered the contest too late to enter anyprimary. The party bosses wanted him and decided to try to sell him as a conservative Democrat for the South, even though Wallace, running third party, was far likelier than Humphrey to get votes of Southern Democrats who were not still totally loyal to Democrats. He lost.

I've only been looking at Democratic nominees in Presidential elections, start with 1948 and I've only gotten as far as 1968 so far. So, I don't know if there is a more recent example--other than Sanders in 2016, of course--but even 1968 was not a century ago.