Eh, there’s several ways to secure electronic tabulation - in fact, most states do use electronic tabulation with checksums and tons of layered security (including airgaps). The paper ballots are kept as a backup in these cases of course. If the checksum doesn’t match or some other metric is off, you can recount the votes using the paper ballots.

For example, Washington state’s process of tabulation:

The votes are tabulated by certified individuals using machines that are not connected to the internet at 8 pm on election day. The machines are individually certified by federal and state authorities and independently tested in NIST laboratories. As votes are tabulated, voters can track their ballot’s progress through the VoteWA system.

An independent study by The Heritage Foundation reviewed 10.6 million ballots cast in the state of Washington between 2004 and 2010 and only found seven fraudulent votes attempted by mail. “I have not seen any new fraud since moving to the system… in my 14 years, we have only had two fraud cases, and one called to inform and apologize,” said Marianne Nichols, Pend Oreille Auditor. “We rarely come across cases of double-voters or attempts to vote another person’s ballot,” added Julie Anderson. “Most cases are voter mistakes, not an attempt to commit fraud or undermine an election.”

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