I was reading that there is much uncertainty about what would happen to all the mail-in votes that have already been cast which have his name on them if Trump died or withdrew. In the accounts I have read, it is not clear if any votes cast for him would automatically transfer to another nominee. Even the votes cast for Biden could be in some doubt, since saying you prefer Biden to Trump does not inherently say you prefer Biden to A. N. Other.

On the UK side of the ocean this passes almost in a single comment, but presumably it is exercising people on the US side more. I'd be interested in hearing comments on it.