I think I’m with Thomas Kwa on this one, mainly because I see 0.1% as a really low bar. E.g.
let’s say ≥10% chance that the election is close enough to turn on “random-ish things” rather than “structural factors” (random-ish things would include [as discussed in other answers] weather on election day, decisions of particular individuals that “could have gone either way” [to run or not, to endorse or not, to assassinate or not, to release incriminating information on a candidate right before election day or not, whatever Patient Zero of COVID-19 was doing at the time], etc.);
and out of those ≥10%, it seems reasonable to me to guess ≥1% chance that a re-roll of quantum randomness would flip the result.
So that gets us above 0.1%.
I think my guess would be more like, I dunno, 1%–10%?
I think I’m with Thomas Kwa on this one, mainly because I see 0.1% as a really low bar. E.g.
let’s say ≥10% chance that the election is close enough to turn on “random-ish things” rather than “structural factors” (random-ish things would include [as discussed in other answers] weather on election day, decisions of particular individuals that “could have gone either way” [to run or not, to endorse or not, to assassinate or not, to release incriminating information on a candidate right before election day or not, whatever Patient Zero of COVID-19 was doing at the time], etc.);
and out of those ≥10%, it seems reasonable to me to guess ≥1% chance that a re-roll of quantum randomness would flip the result.
So that gets us above 0.1%.
I think my guess would be more like, I dunno, 1%–10%?