Auschwitz
To the extent that the use of the phrase “Are you now or have you ever been…” is an almost-too-obvious sign in a movie, TV show, or book that “You should be thinking McCarthyism right now.”
ETA - also, if you were “in the trenches” with somebody, you were doing real work in crappy conditions and can speak to their character.
Iraq is described as America’s new Vietnam.
Various political leaders have been described as the “George Washington” of their respective countries.
“Gordian Knot” for a thorny problem that has a simple, outside-the-box solution.
“Only Nixon can go to China” is still used from time to time.
I’ve heard epic things referred to as “Homeric”.
As viewers of professional wrestling will tell you, it’s still in use, every Monday night from 9-11 Eastern.
Presumably “the reinvention of the wheel” actually happened at some point.
Nuclear disasters tend to be popular. “It was almost a Three Mile Island,” or “We would have another Hiroshima, only twenty times as bad” (film only).
“Agincourt” for a battle in which technological advances turned a closely matched event into a slaughter (regardless of the historical accuracy of that view of Agincourt).
Jonestown used to describe a mass suicide
“a marathon session”
“put your John Hancock here”
“my cross to bear”