According to The Real Majority: An Extraordinary Examination of the American Electorate by Ben Wattenberg and Richard M. Scammon, during the primary of 1968 Robert Kennedy and Eugene McCarthy were never ahead of Nixon. Humphrey sometimes was. Also, about 90% agreed that "student disturbances" were a major problem. They did not say that about the War on Vietnam. I was in the anti war movement back then, but I never imagined that we had majority support.Wow, you missed the point. It wasn't that McCarthy "won" it was that he was competitive at all. An incumbent president should NEVER face a serious challenge, and ones who have (Ford, Carter, Bush-41) have usually gone on to lose. Yet Johnson only pulled out 48% of the vote to McCarthy's 42%. This shows how completely unpopular Johnson had become, and why he withdrew from the race.
Actually, RFK won a bunch of important primaries and probably would have been selected if he hadn't been assassinated.
Back in those days, few states held primaries, most delegate were chosen through caucus.