Three states loom largest in this concern: Michigan, Wisconsin and Pennsylvania. All three are key battlegrounds that have made a rapid and politically fraught push to expand voting by mail this year. All have Democratic governors and Republican legislatures that have fought bitterly over election rules in state and federal courts. All have a limited ability under state law to count or process mail ballots before the polls close. Other quirks, like a “naked ballot”–a legitimate ballot that a voter has failed to enclose in the required security envelope–may cause further uncertainty; a Pennsylvania court ruled this year that such ballots would not be counted in that state, which Trump won by just 44,000 votes. It all could add up to a presidential race that’s too close to call for days or weeks.

But for these delays to matter, the tally would have to be very close, and the presidential race would have to hinge on those three states. Current polls do not show a particularly tight race in those states, nor nationwide. And the polls have been far more stable, with far fewer undecided voters, than they were in 2016. Faster-counting states like Florida and Arizona, which have demonstrated the ability to rapidly tabulate large volumes of mail ballots, could well decide the election, rendering any uncertainty in the Rust Belt irrelevant.