I think you're right about Goldwater's later years. Here's an excerpt from the Wikipedia article about him:

By the 1980s, with Ronald Reagan as president and the growing involvement of the religious right in conservative politics, Goldwater increasingly showed a libertarian streak that put him at odds with the Reagan Administration and religious conservatives. Goldwater viewed abortion as a matter of personal choice, not intended for government intervention. As a passionate defender of personal liberty, he saw the religious right's views as an encroachment on personal privacy and individual liberties. In his 1980 Senate re-election campaign, Goldwater won support from religious conservatives but in his final term voted consistently to uphold legalized abortion. Even in matters of foreign policy, Goldwater disagreed with Reagan and his supporters; he opposed the decision to mine Nicaraguan harbors. Notwithstanding his prior differences with Dwight Eisenhower, Goldwater in a 1986 interview rated him the best of the seven Presidents with whom he had served.

After his retirement, in 1987, Goldwater described the conservative Arizona Governor Evan Mecham as "hardheaded" and called on him to resign, and two years later stated the Republican Party had been taken over by a "bunch of kooks." In a 1994 interview with the Washington Post the retired Senator said, "When you say 'radical right' today, I think of these moneymaking ventures by fellows like Pat Robertson and others who are trying to take the Republican Party and make a religious organization out of it. If that ever happens, kiss politics goodbye." He said about Jerry Falwell, founder of the Moral Majority, "I think every good Christian ought to kick Falwell right in the ass."

In the 1990s he became more controversial because of statements that aggravated many social conservatives. He endorsed Democrat Karan English in an Arizona congressional race, urged Republicans to lay off Clinton over the Whitewater scandal, and criticized the military's ban on homosexuals: "Everyone knows that gays have served honorably in the military since at least the time of Julius Caesar." He also said, "You don't have to be straight to be in the military; you just have to be able to shoot straight." In 1996 he told Bob Dole, who mounted his presidential campaign with luke-warm support from hard-line conservatives, "We're the new liberals of the Republican Party. Can you imagine that?"

It's fascinating to realize just how far the Republican Party has lurched away from its former principles.

--Socialist With A Gold Card