Joe Biden heads into Election Day preferred by voters who have already cast their ballots early. President Trump has a lead among those who plan to show up on November 3. So will Biden's lead hold up? If we trot out the old horserace analogy, Biden has a lead, but we still don't know how long the track is. We need to see how big that Election-Day vote will be.
So we took our baseline state model estimates from our initial polling, which sums to Biden holding an Electoral College lead heading into Election Day, and also estimated what it would take for each candidate to ultimately win.
We estimate from our polling that Mr. Trump is doing, on average, over 30 percentage points better among likely Election-Day voters than early voters. We know the approximate size of the early vote so far, and we vary the potential size of the Election-Day vote to explore two scenarios.
In our Republican-surge scenario, the size of the Election-Day vote is relatively large, so given that these voters break for Mr. Trump, it mitigates Biden's early-vote edge, and Mr. Trump inches out close wins in enough states to go over 270. (We increased the size of the Election-Day vote by an average of seven points in this scenario, while keeping vote preference among early voters and Election-Day voters fixed.)
But it doesn't take much for this to break big the other way. If some of the people planning to vote on Tuesday decide not to show up, and the size of the Election-Day vote decreases by an average of three points from our initial estimates, the net result is pretty dramatic. Given Biden's overall preference leads, nearly all the competitive states either flip to Biden or stay in his column, giving him a comfortable win.
In our baseline scenario, Biden has a narrow Electoral College edge with many states toss ups.
You can view all 50 state estimates here.
So with the Biden campaign having banked so many early votes, Mr. Trump is very reliant on robust turnout among his supporters this Tuesday. Election-Day voters support the president in large numbers in the most competitive states — the question is, will they follow through? And of course, there's also the question of whether Democrats will match them. Many Democrats have voted early, but many more also remain to still cast ballots, including many younger voters on whom the Biden campaign depends.
And finally, with all the legal wranglings over ballots and deadlines this year, the estimates do not account for the effects of those proceedings, if any, on the number of ballots ultimately cast and counted.