IIRC a relative of Barack Obama voted via absentee after sending the ballot in and before election day. Hawaiian official considered it an official vote since she was alive when she mailed it in.
THis is what I was going to say. Besides, it’s the vote itself that matters, not whether the person lives to see the result. It’s like paying taxes: once you’ve sent the check, the government isn’t going to send it back if they discover you’re dead on April 16th.
At midnight on election day they have to stop the collection of all votes and start the process of determining if anyone who voted has died since casting their vote. Once that process completes they have to start the process of determining if anyone who voted has died during the time they were determining if anyone who voted has died since casting their vote. Once that process completes they have to start the process of determining if anyone who voted has died during the time…
TriPolar: Again, a reduction ad absurdum is not a legitimate rebuttal to a general principle.
The county bureau of records could coordinate death certificates with the Registrar of Voters, without going to the preposterous level you describe.
The question has been answered: this isn’t actually done.
This is one of Zeno’s Paradoxes, isn’t it?
Don’t give them ideas…
Jimmy Carter said some towns in Georgia allowed widows to vote twice , 2nd vote was for dead husband. He put a stop to that
It varies from state to state.
The answer depends mostly on where the voter is registered, because American election laws and procedures are for the most part determined by the individual states, even in elections for federal office. In New York, for example, an absentee ballot can be challenged on the grounds that the voter died before Election Day (in-person early voting is not available in New York). Minnesota, which has both early voting and absentee voting, allows for a challenge in both cases if proof is presented to an election judge that a voter died before 7 AM on Election Day.
But most states do count the votes of the recently deceased, according to the bi-partisan National Conference of State Legislatures (NCSL), an NGO that tracks US state election laws. In the case of Florida, state law spells it out clearly: “The ballot of an elector who casts an absentee ballot shall be counted even if the elector dies on or before Election Day.”
The Lawrence County Democratic Party is insuring the OP hypothetical will not happen:
Today we got, in the mail, a suprisingly sensible note from the U.S. Postal Service suggesting that we mail in our ballot early. But because our ballots haven’t been printed yet (mailing out was supposed to be this coming Monday), that post card was worthless.
Hardly anyone was gong to vote Green in swing states, both because of anti-Trump sentiment and because, I think, their ticket is weaker than the last one. Getting mail ballots out and back early is much more important. What a Democratic own-goal!
In case you are thinking about dropping off your ballot at a Pennsylvania lock box shortly before election day, think again. The GOP says that there is no provision in law for those boxes and is in court trying to get anything you put in one invalidated.
There is a similar Green Party access challenge delaying Wisconsin ballot printing 
In 2008, Obama’s grandmother voted for him by mail, but then died before Election Day. Some conservatives’ first reaction was to say that they had better make sure her vote doesn’t count.
More on dead voters (and how it’s not really an issue this year in the presidential election):