Even though CA indicates that illegals can only vote on local issues, I have been unable to find anything in CA Election Code that indicates they use different ballots or have personally identifying info on ballots used.
So as long as you’re registered, you get the same ballot, mark prez (even though you’re not supposed to), and the ballot goes in the pile to count.
No way to prove after the fact how many.
In CA, based on how their system works, ALL illegals there could’ve voted.