I was a 17 year old McCarthy field worker in NH in December and January 67-68.
Glorious times.
Most people don't know that Bobby held back until LBJ quit, but we were not working for RFK, not even a little bit - we were SO PISSED, it felt like we did the heavy lifting to make something happen that no one believed possible, so that "another Kennedy" could step in, pick up our chips without asking, and be the nominee.
As late as the awful night of June 4, 1968 it was still a race, McCarthy won Oregon that night but RFK won California.
Of course, the Kennedy delegates were all party men, by the time the sun rose on June 5, most of them were already declaring for Humphrey.