Not to be to picky here, but my recollection was that RFK's strong showing in the primaries was what led LBJ to not seek the nomination for president. It was LBJ who put his influence behind Humphrey who won the nomination and ran against Nixon in 1968. McCarthy lost the nomination after he cried at some event.
Nope, it was McCarthy. Kennedy sat out for months, while McCarthy organized and worked his tail off until he shocked Johnson with a near-win in the first primary. Kennedy then jumped in, infuriating McCarthy and his campaign people, and the two battled it out trading primary victories until Sirhan shot Kennedy.In those days, state party apparatus (and unions) controlled more delegates than there were to be won in primary elections, and Humphrey mined that source for enough delegates to winthe nomination. LBJ only belatedly and not very enthusiastically endorsed Humphrey. I believe LBJ held out hope for a deadlocked convention where he would be asked to be the nominee until the very last and it became apparent NOBODY in his party wanted him anymore.
As for the crying, that was Sen, Edmund Muskie of Maine, I think in ‘72.