Two days before Wednesday’s US election (AEDT), the FiveThirtyEight national aggregate gives Joe Biden an 8.6 percent lead over Donald Trump (52.0 percent to 43.4 percent). In the key states, Biden leads by 8.3 percent in Wisconsin, 8.2 percent in Michigan, 4.8 percent in Pennsylvania, 3.1 percent in Arizona and 2.2 percent in Florida.
Biden’s lead in Pennsylvania is almost four points below his national lead, and that gives Trump hope of pulling off an Electoral College/Popular Vote split, as occurred at the 2016 election. Pennsylvania is the most likely the “tipping-point” state that could put either Trump or Biden over the magic 270 Electoral Votes.
If Biden loses Pennsylvania, but wins Michigan, Wisconsin and Arizona, he would have 269 Electoral Votes, one short of 270. Either Maine’s or Nebraska’s second Congressional District could, in that scenario, give Biden the narrowest of Electoral College wins. These states award one Electoral Vote to the winner of each of their districts, and two to the statewide winner. All other states are winner-takes-all.

