Donald Trump on Saturday unleased some of his classic arguments for “full presidential immunity” from all criminal charges, as his first criminal case is bearing down on him. Trump, who is preparing himself for the launch of his first criminal trial, has denied that he falsified financial records to hide a payoff to a woman he had an affair with. He has also sought to argue presidential immunity in the case, despite the payoff predating his presidency, but that request was rejected by the court. Still, just days before the trial is set to begin, the former president took to his social media si…