Donald Trump’s attacks on Joe Biden’s age and mental fitness have backfired. Trump, calling Biden “Sleepy Joe” and unfit for the presidency due to his age, faced criticism when he mistakenly claimed that Biden could lead the U.S. into “World War Two” and suggested he defeated Barack Obama in 2016.

Biden, at 80, is the oldest president ever, while Trump is 77. Trump’s comments have had little impact on public opinion. Biden and Trump both assert their fitness for office and even support competency tests, but the age issue remains.

Democrats argue that Biden’s age receives undue attention, but a recent poll found that only 34% of voters believe Biden would complete a second term, while 55% think Trump would complete four years. Concerns about leaders’ age extend beyond the presidency to figures like Mitch McConnell and Dianne Feinstein, prompting discussions about age limits in office.