One of the great tragedies of 1968 was the vidtory of Cranston, a hard core leftist, over Rafferty, a solid conservative. A lot of liberal Republicans were unhapppy with the primary result, and some supported Cranston, who won by a narrow margin.
During World War II, Rafferty was classified 4-F because he had a bad leg and walked with a cane. But on VJ Day, Rafferty threw away his cane. This came out in the course of opposition research, and once the Democrats made it public, Rafferty looked like a hypocrite.
That's why Cranston picked up so many Republican votes.