There was no "religious right" in 1964, unless you want to count Episcopalians. Contrary to the way some politicians wear their religion on their sleeves these days, being a Christian (or a Jew, or a Catholic) was a personal thing in the 1960s. You didn't find newsies following candidates into church with their cameras - and for sure you didn't see politicians carrying 10-pound bibles for effect.
I count the religious right of the sixties as the very strong anti-communist electorate, and largely on the basis that Communism was Godless ( I had a liberal friend in college who scornfully lampooned the point of view as “Kill a commie for Christ”), that supported the Viet Nam war,etc., as opposed to the Episcopalians who were sending people to Cuba to cut sugar cane, etc. A bloc of voters that was led around by Jerry Falwell or Ralph Reed has never existed IMO, if that’s what you mean by “religious right.”