President Joe Biden, who at 80 has had to confront questions about his age and mental acuity as he launches a reelection campaign for president, once ran a campaign that sharply attacked his opponent’s age.

In 1972, Biden, then 29 years old and a local Delaware councilman, was running against incumbent Republican Sen. Cale Boggs who was 63 years old, a former two term governor and the state’s senior senator.

“Cale doesn’t want to run, he’s lost that old twinkle in his eye he used to have,” Biden said of Boggs, who had originally wanted to retire but was persuaded to run for reelection.

Biden used his opponent’s age against him in a way that was so explicit, one local reporter dubbed his approach, “Dear old dad.”

Biden was running to become one of the youngest people ever elected to the United States Senate. Now, the president is already the oldest person ever to serve in the office of the presidency, and, if reelected, would leave office at the age of 86. That would best the next oldest president by more than 9 years if he served a full second term.

The president’s age has been “omnipresent” in nearly every conversation, CNN reported in February, though that notion was disputed by a White House spokesperson.

In response to a request for comment, White House spokesman Andrew Bates told CNN that Biden has made “historic progress” that has been “enthusiastically welcomed by younger Americans – including his unprecedented investments in fighting climate change, his first-of-its kind police reform executive order, his actions to support community policing and decriminalize marijuana, and getting more Americans health coverage than ever before.”

In 1972, advertisements for Biden in local newspapers and on the radio hammered home a line, “he understands what’s happening today.” The ads targeted Boggs’ age by bringing up past historical topics from Bogg’s “generation,” like Joseph Stalin ruling Russia, jazz musicians using heroin, the development of the polio vaccine, and taxes from the 1940s.

“Cale Boggs’ generation dreamed of conquering polio, Joe Biden’s generation dreams of conquering heroin,” read one newspaper ad. “To Cale Boggs an unfair tax was the 1948 poll tax. To Joe Biden an unfair tax is the 1972 income tax,” read another.

One radio advertisement targeted Boggs as too focused on past threats from Russia, while ignoring domestic issues like crime.

“One of the biggest differences between Cale Boggs and Joe Biden is the things they worry about,” said the radio ad. “In Cale Boggs’ day when Stalin ruled, Americans had visions of the Russian soldiers in our streets. In Joe Biden’s day, Americans have visions of American criminals in our streets. Joe Biden, he understands what’s happening today.”

The approach drew pushback from Sen. William Roth, a Delaware Republican who Biden would work closely with for the next 30 years, according to the News Journal, and commentary from the media at the time.

Biden eventually won that race with the Associated Press declaring, “Biden stressed age to defeat Boggs.”

As Pulitzer Prize-winning journalist Norm Lockman wrote, “The new campaign strategy, ordered by Biden himself, eases off the strident tub-thumping and finger pointing and uses an approach that says, in effect, “Dear old dad may have been right for his time – and I love him – but things are different now.’”

This story has been updated to reflect Biden’s announcement.