The 1964 conventions took place

[wnylib]

less than a year after JFK's assassination. No Republican was going to win the WH that year.

Goldwater's candidacy was the beginning of the R shift away from centrism and toward the far right. Republicans turned away from the centrism of Eisenhower and Rockefeller and kept moving farther right in order to gain more votes and members with a more populist appeal.