Inventing people and getting someone to show up and vote as them isn't what you'd do with write access to voter rolls. Instead you'd want to remove or corrupt existing voter information. This would cause huge delays at polling places as people protest their inability to vote and go through the provisional ballot process. If every voter went through with that we'd be fine as enough provisional ballots to tip an election means they have to get validated. The likely outcome however would be people giving up on voting because they're out of time and/or patience and leaving before they ever get a ballot, provisional or not.
Target voters in enough locations likely to have large turnout for your opponent and you'd be able to tip the election in your favor, so long as you had any chance at all to win. This wouldn't be enough to help someone who is going to lose 83/17 but a 60/40 loss could be tipped your way and that's what most outcomes in the US are.
> Instead you'd want to remove or corrupt existing voter information. This would cause huge delays at polling places as people protest their inability to vote and go through the provisional ballot process.
Do you think if it really happened we'd notice it? So far I am not aware of any case of vote being disrupted to any noticeable measure along the scenario you describe, anywhere. So this appears to be pure speculation.
> This wouldn't be enough to help someone who is going to lose 83/17 but a 60/40 loss could be tipped your way and that's what most outcomes in the US are.
Yet there is, as far as I know, not a single case of election ever being tipped this way. By other forms of fraud - surely, though even then it's very hard to connect specific instances of fraud to specific outcomes - but this kind of fraud, never happened.
Target voters in enough locations likely to have large turnout for your opponent and you'd be able to tip the election in your favor, so long as you had any chance at all to win. This wouldn't be enough to help someone who is going to lose 83/17 but a 60/40 loss could be tipped your way and that's what most outcomes in the US are.