I know that's a stupid question...but to anyone who thinks it's ok, or allowable for a state to decide to change what day the election ends on, and the allowance of mass mail-in ballots, ask those same people if they'd be ok if a state decided months before the Presidential Election to allow text message voting....or voting through Facebook, email or twitter.
Then ask them if they'd be ok with it if it was a governor and attorney general of one party with a majority of officials of that same party all making that same decision.
The Presidential Election needs to have input from the federal government and even from the Supreme Court. We have an electoral college system that really does bring it down to the swing states, so when a swing state changes their rules, it has an impact on all 50 states....some people vote in states where their vote is irrelevant because the state is a dominant blue/red state, but the rules that other states make impact the voters in the other states.
If you think the Supreme Court should never allow a state (especially swing state) to change to email voting, text voting, smoke signals or whatever for a federal election, than you should agree that changing to mail-in voting or changing the date would be just as intolerable.
Sorry to inform you, but emailing (instead of postal mailing) absentee ballots was in fact allowed. I don’t know all of the jurisdictions that allow this but I can confirm 100% it is possible. It’s horribly insecure.