>> reporter: that's the law? >> republicans made and refused to change. >> reporter: a key point. especially in pennsylvania. >> this is the most significant modernization of our elections, elections code in decades. >> reporter: expanded vote by mail legislation passed before the pandemic. in 2019. by the republican legislature. these were republican rules. >> the refusal to count those mail votes early and be prepared really hurt the country. and if you can't get the ballots counted accurately, efficiently, expeditiously you create this space for trump and his squad and these goons to go out there and plant lies, to try to steal this election. >> we're going to prove to the american people that arizona is trump country! [ cheers ] >> reporter: it was happening most notably in swing states. in arizona, there was