How did "Liberal" become a dirty word?

I'm not a conspiracy theorist, and neither is the author of this Sept 2004 article: Tentacles of Rage: The Republican propaganda mill, a brief history LEWIS H LAPHAM / Harpers Magazine v.309, n.1852.

but it is interesting to see how things could change so much from 1964, when Barry Goldwater's "conservatism" was really seen as out of touch from the mainstream, enough that 61% of the popular vote went against him.

That said, note how I am from such a different generation than the people who write these articles. To me, so-called conservative concepts like small efficient government or a strong defense sound like common sense, a biological consequence of Steven Pinker's idea of the "tragic view" of our genes. We are by nature deceitful, power-grabbing, violent animals, and the role of government is to keep that in check. The 1960s "liberals" were wrong about it, in just the way they were wrong about boys and girls being identical except for upbringing. People and ideas should just move on.