Frontrunner Joe Biden and an increasingly struggling Donald Trump traded jabs Tuesday hours ahead of a first presidential debate that promised to be as nasty and unpredictable a clash as American voters have ever seen.Before they’d even met on the stage in Cleveland for the first of three 90-minute live television clashes, Biden made public his tax returns to capitalize on revelations by The New York Times that the billionaire Trump avoided paying almost any federal income taxes for years.Trump’s reported mastery of loopholes to pay just $750 in federal tax during the first year of his presidency has given Biden an opening to paint the Republican as a phony when he says he represents America’s working classes. By contrast, Biden’s returns show that he and his wife Jill paid a hefty $299,346 in federal income taxes for 2019. While Biden tees up what is likely to be a central weapon in the debate, Trump’s team leaned in on its lurid narrative that the Democrat challenger is senile and needs help to get through the debate.Trump has repeatedly demanded that Biden take a test for performance enhancing drugs.And on Tuesday, his campaign, echoed by Trump-friendly Fox News, launched into new conspiracy theory territory by loudly demanding that Biden be checked for a secret earpiece — presumably to give him answers in the debate.”Joe Biden’s handlers several days ago agreed to a pre-debate inspection for electronic earpieces but today abruptly reversed themselves and declined,” Tim Murtaugh, Trump 2020 communications director, said in a statement. COVID and taxesTrump flew into in Cleveland Tuesday afternoon ahead of the debate, with a senior official on Air Force One telling reporters: “He’s ready to go.” The official said Trump was bringing former New York mayor Rudy Giuliani — now a controversial lawyer for the president — and mixed martial arts fighter Colby Covington as guests.The pre-game trash talk gave a flavor of what the two camps are trying to achieve.Trump, behind in national and swing state polls, is considered a master at changing the subject and stirring outrage.Biden wants to keep the debate firmly fixed on Trump’s biggest liabilities — the more than 200,000 coronavirus deaths and the tax avoidance uproar.COVID-19 restrictions will give the debate a streamlined look with a smaller audience. Naturally, there won’t be the once standard — even if forced — show of goodwill in shaking hands.What Americans will get, however, is a chance finally to see Trump, 74, and Biden, 77, side by side.And Trump, who fancies his skills as a verbal pugilist, is expected to hit hard and low. Blue collar boast The president is sure to go heavy on previous claims that Biden’s son was involved in corruption in Ukraine. Last year Trump was impeached for using the power of his office to try to pressure the Ukrainian government into publicly backing that theory.Biden, as frontrunner, wants to stay steady, but he has a reputation for losing his cool when challenged in public. Many Americans are keen to see whether the would-be president can stand the heat of a Trump firestorm.”I hope I don’t get baited into a brawl with this guy, because that’s the only place he’s comfortable,” Biden conceded.But Biden will also go after Trump in a personal way, painting him as a spoiled playboy who only poses as a friend of the white working class that helped him get elected in 2016.Biden, who spent his early childhood in the rough-edged town of Scranton, Pennsylvania, is increasingly mocking Trump’s glitzy New York roots, calling it a “Scranton vs Park Avenue” election.The strategy does appear to have some traction in Pennsylvania at least: on Tuesday a new Washington Post-ABC News poll showed the former vice president pulling ahead in the battleground state, which Trump won in 2016.Topics : The campaign also claimed that Biden had asked for “multiple breaks during the debate, which President Trump doesn’t need.”Biden’s deputy campaign manager Kate Bedingfield called all this “absurd” and shot back with her own bit of rumor mongering, claiming that Trump’s team had tried unsuccessfully to ensure that the debate moderator, Fox News’ Chris Wallace, would never mention the number of US deaths from COVID-19.”See how easy that was to try to throw up a distraction?” she was quoted as saying by Politico. Supreme Court silver bullet? The president arguably has little to lose: his hardcore support is already baked in and Americans are by now almost incapable of feeling shocked by his convention-wrecking insults and well documented torrent of exaggerations or outright lies.But he also goes to Cleveland with what he hopes will be a silver bullet — his nomination of conservative judge Amy Coney Barrett to replace the late liberal icon Ruth Bader Ginsburg on the Supreme Court.If Barrett is quickly confirmed, as the Republican-led Senate expects, Trump will have tilted the highest court firmly to the right for years to come.Democrats are crying foul over the rushed timing on the eve of an election, but Trump expects the power play to energize conservatives.