“Barry Goldwater, iirc, ended his career in a much different key than his song in 1964. “
Elaborate on what you mean.
I didn't follow Goldwater's career closely, but seems to me he ended up less than socially conservative.
In that regard I might mention Mayor Pete, opposition to evangelicals (said he will "fight them every step of the way"), support for legalized marijuana & abortion.
In 1989 he said the Republican party had been taken over by "a bunch of kooks" -- referring to evangelicals.
Some say his second wife was somehow responsible...
So far as I know, Goldwater was always solid on national defense (well, except for Mayor Pete), with the 1986 Goldwater-Nichols act passing 383-27 in the House, 95-0 in the Senate.
Goldwater did oppose reckless foreign adventures, even Ronald Reagan's 1982 mining of Nicaraguan harbors.
In 1960, Goldwater wrote the book, Conscience of a Conservative, but I think he missed a key point that helps define American conservative today.
For Americans, the word conservative means not just the Constitution, but also the Bible, and not necessarily in that order.
In the end, Goldwater's conscience was more libertarian than conservative.