On Monday, Hillary Clinton released an ad that harks back to Cold War-era politics, in which the threat of nuclear war cast a dark, mushroom-shaped cloud over every election. Again.

Clinton's newest ad, titled “Daisy,” reprises a 1964 ad of the same name. One of the more famous political ads of its time, it apparently only aired on TV once (though this Fix reporter wasn't born until several decades later, and is unable to confirm).

The 1964 ad showed a young girl counting flower pedals as she picked them one by one, then an ominous countdown to a nuclear explosion, followed by a plea to vote for Lyndon Johnson on Election Day. The message was blunt: A vote against Johnson was a vote for nuclear war.

Political ads have come a long way since then. Some of them — ones that don't involve nuclear explosions — can even be funny. But Clinton's new ad uses the same imagery, and even the same actress.

Monique Corzilius Luiz, who played “The Daisy Girl” in the original ad, talks about how she thought nuclear war was a threat of the past, that has suddenly been made real again by Trump. The ad then shifts to an exchange that took place on MSNBC's “Morning Joe,” in which host Joe Scarborough tells a story revealing Trump's apparent startling lack of knowledge about using nuclear weapons.

It's part of a strategy team Clinton has been using for months — casting Trump as a combination of unhinged and uneducated on the issues. And to anyone who remembers the 1964 “Daisy” ad, it probably rekindled those old feelings of oppressive fear, the kind of fear that can drive voters to pick a candidate based on the strength of their national security proposals.

Clinton's team used a similar technique with another spot released in July, “Confessions of a Republican,” in which actor Bill Bogert listed the reasons he's unable to vote for Donald Trump, despite being a registered Republican. The ad reprised another 1964 spot in which Bogert discussed the reasons he couldn't vote for 1964 Republican nominee Barry Goldwater.

The star of the classic "Confessions of a Republican" ad reenacts his 1964 spot denouncing Barry Goldwater. (Hillary Clinton)

“Trump says, 'We need unpredictability' when it comes to using nuclear weapons,” Bogert laments in the 2016 version of the black-and-white ad. “When a man says that, he sounds a lot like a threat to humanity.”

It's a pitch that worked five decades ago. Clinton is betting it lands the same way today.