Vietnam wasn't an issue in 1964.
It was. This one-line joke was told a year or two later by an elementary-school buddy of mine:
"Do you realize that if Goldwater had been elected, we'd be bombing Hanoi?"
(Johnson had started his escalation and bombing shortly after the election.)
It most certainly was though not to the extent it was to become when we got so totally involved. But even if you were correct, the point I was making was that Johnson, like Democrats Wilson and FDR before him, ran as the "peace" candidate when all the while he was planning on getting us more deeply involved militarily in Vietnam.