US President Joe Biden got his start in politics by hammering a 63-year-old opponent for being too old to serve. Now the oldest-ever US commander-in-chief, Biden is being bashed by Republicans and Democrats alike for being over the hill.

Biden was 29 years old when he was elected to represent Delaware in the US Senate in 1972. His campaign offered a preview of the highly personal style of attack ads that would come to dominate American politics in the years since, with one radio ad describing his opponent, incumbent Republican Cale Boggs, as being trapped in the past.

“One of the biggest differences between Cale Boggs and Joe Biden is the things they worry about,” the ad stated, according to a CNN report on Tuesday. “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 ad concluded.

“Cale doesn’t want to run,” Biden told the Delaware Evening Journal on the campaign trail. “He’s lost that old twinkle in his eye he used to have.”

The strategy paid off, with the Associated Press reporting that Biden “stressed age to defeat Boggs” after he won by a sixth of a percentage point.

Biden is now 17 years older than Boggs was at the time of the election, and faces much of the same criticism he heaped on his Republican opponent in 1972. Biden has been accused by Republicans of focusing excessively on countering Russia in Ukraine, while crime rates rise in American cities. While Biden once described Boggs as losing “that old twinkle in his eye,” Biden’s opponents point to his verbal slip-ups and visible confusion as evidence that the president is experiencing advanced cognitive decline.

Biden announced on Tuesday that he will seek re-election in 2024. Should he be successful in that endeavor, he will be 86 at the end of his second term. Biden is already the first US leader to serve into his ninth decade, and a Reuters poll published on Tuesday found that 61% of registered Democrats felt that he is too old to continue working in government.

Politicians have aged since Biden first took his seat in the Senate. The 2020-2022 Congress was the oldest in history, with around a quarter of its members over the age of 70. In 1972, by contrast, just 8% of US lawmakers were over 70.

Americans in general are living and working longer than they were in the days of Biden’s youth. Life expectancy has risen from 71 years in 1972 to 79 in 2022. According to the Washington Post, the share of octogenarians in the US workforce has increased from 110,000 in 1980 to 734,000 in 2019.