Washington (AFP) – With Tuesday’s US presidential election only days away, Donald Trump, Joe Biden and their top surrogates were barreling through the crucial states of Michigan and Pennsylvania on Saturday, digging deep as they pressed their closing arguments.Underscoring the high stakes — and the disruptive impact of the coronavirus pandemic — a record 90 million early votes have already been cast, as the bruising contest heads toward the biggest turnout in at least a century. For the first time since the start of the campaign, Biden, 77, will be joined on stage in Michigan by his former b…