Taking a line out of Donald Trump’s playbook, Joe Biden offered his rival a tongue-in-cheek birthday greeting on X on Friday, saying: “Happy 78th birthday, Donald. Take it from one old guy to another: Age is just a number.” The president then coupled his thoughts with a caustic video sarcastically touting “78 of Trump’s historic … ‘accomplishments’” before a Biden re-election campaign spokesperson added: “On behalf of America, our early gift for your 79th: making sure you are never president again.” Biden’s message comes as his campaign attempts to inject some wit and zippy one-liners into its output, critiquing his presidential predecessor beyond baseline warnings about democracy over other topics such as Trump’s hairstyle, his hawking of Bibles and his energy levels at his New York trial, where he frequently closed his eyes before being convicted of falsifying business records related to hush-money payments delivered to adult film actor Stormy Daniels. Trump’s conviction came less than two weeks before Biden’s son, Hunter, was convicted on charges related to him buying a handgun while being a user of crack cocaine. Taking the age issue to the campaign wrestling mat is a strategy that comes with risks for both candidates. For Democrats, a willingness to embrace it marks a change of direction. For months, the Biden campaign has played down questions about Biden’s mental acuity. But it’s now confronting the issue head-on after polls showed that 86% of Americans say the 81-year-old president is too old for a second term compared with 59% for Trump, fewer than four years his junior. But after Biden appeared to wander off several times during his visits to Europe last week, and was steered back into position by the first lady, Jill Biden, or other world leaders, the age issue is again bubbling to the surface. There was also a hard-hitting, 3,000-word Wall Street Journal article recently that quoted numerous lawmakers who said they had witnessed Biden “slipping” and experiencing good and bad moments. The Journal said the White House had “kept tabs” on Democrats who participated in the story and encouraged them to call back to emphasize Biden’s strengths. At a campaign event in Wisconsin hosted by older supporters of Biden and his vice-president, Kamala Harris, the first lady advanced the argument that her husband’s age is an asset. “This election is most certainly not about age,” Jill Biden said. “Joe and that other guy are essentially the same age. Let’s not be fooled, Joe isn’t one of the most effective presidents of our lives in spite of his age, but because of it.” Meanwhile, for the former president, turning 78 on Friday meant a CNBC report quoting CEOs of various businesses who had met with Trump and found him to be “remarkably meandering”. The CEOs found that Trump “could not keep a straight thought [and] was all over the map”, including one who added that the former president “doesn’t know what he’s talking about” when it comes to explaining how he would accomplish any of his policy proposals, the report asserted. Trump otherwise spent Friday addressing Club 47 fan club members at a convention center in West Palm Beach and going after his rival. “Our country is being destroyed by incompetent people,” Trump said while calling for all presidents to pass aptitude tests. That came a day after Republicans in Congress sang their own rendition of Happy Birthday and presented Trump with a cake and gifts during his first visit to Capitol Hill since his supporters attacked the Capitol building on 6 January 2021, weeks after Biden defeated him in the 2020 presidential election. Trump himself didn’t seem too thrilled by the prospect of a close-to-milestone birthday. He told supporters at a rally in Las Vegas last week: “There’s a certain point at which you don’t want to hear ‘happy birthday’. You just want to pretend the day doesn’t exist.” In spite of the bickering over age, the two candidates have agreed to the rules of their first TV debate scheduled for 27 June. Host network CNN released details it hopes will keep the candidates within the realm of a debating format after both candidates refused to share a stage with party rivals during the primary season. According to CNN, Biden and Trump have agreed to a 90-minute debate with commercial breaks, during which they will not be allowed to consult campaign staff. They will appear on a uniform podium stage with left and right positions determined by the flip of a coin. Microphones will be muted except for when it is each person’s time to speak, and each will be provided with a pen, a pad of paper and a bottle of water. There also will not be a studio audience, meaning that the first of two crucial confrontations will be moderated by CNN’s Jake Tapper and Dana Bash who will, CNN said, “use all tools at their disposal to enforce timing and ensure a civilized discussion”. Biden’s campaign on Saturday touted raising $28m heading into an evening fundraiser in Los Angeles featuring former president Barack Obama, talkshow host Jimmy Kimmel, and actors George Clooney as well as Julia Roberts. Meanwhile, Trump on Saturday was campaigning in Michigan, seeking to rally support from people ranging from churchgoing Black voters to a conservative group popular with white supremacists: Turning Point Action.