I'm working at the polls in CA, and can verify this; all critical information is moved by sneakernet with a two-person rule on its handling. Of course, I have

I'm working at the polls in CA, and can verify this; all critical information is moved by sneakernet with a two-person rule on its handling. Of course, I have no information on the security model of the pre-election preparations and post-election tabulation, but luckily results for each polling place are also posted for the public to inspect - media outlets and campaigns can verify the tabulation themselves with a slight delay.