I actually used to audit and run diagnostics on the Diebold voting machines in Kansas. While I know that things may have changed since 2008, we actually did a ton of testing and ran the numbers through two separate verification tests to ensure that the votes match. The main way that the machine records your vote is via the PEB, or Personal Electronic Ballot, which looks a bit like an N64 cartridge. There is also a compact flash card inside the machine which stores the data again for retrieval. When the time comes to tally up the results, the votes are transferred from each individual machine onto the PEB, and then the PEB is inserted into one of the "master" voting booths which then is connected to a printer that can print out the voting record receipt.

While there is a lot that can go wrong, it's generally a pretty fool-proof process since a second set of data is stored on the flash card inside the machines, and we seal the machines with tamper-proof tape to ensure that they are not messed with. You couldn't pre-load results since the number of voters at each precinct that is manually tallied (often by unpaid volunteers from the local retirement home) must match the votes cast on the paper trial.

Finally, you always have the option to vote via paper ballot. The only downside is that we do not actually count the paper ballots unless a race is close enough that the number of paper ballots could mathematically alter the outcome, since it is a bit of a process to fire up the machine that counts the paper ballots. Aka, if someone won by 20,000 votes, we aren't going to scan the 100 paper ballots since there's no way it could impact the outcome.

The night of the election, independent monitors from the political parties are allowed inside the clerks office and can observe the process. The official numbers are also driven inside a locked box back to the clerk's office from each precinct by authorized election officials.

If there are errors, it's likely due to a few things: 1) Calibration. Those machines sometimes have terrible calibration. We specifically instruct voters though to stop voting and ask for a paper ballot if they feel like the machine is not registering their input correctly, and then we take it off to the side for the rest of the day. 2) Corrupt county offices in rural districts that have no monitors and are misreporting numbers. This is a bit less likely since the numbers will be so small (and very Red anyways), but it's a possibility of course. Whether they'd risk hardcore felony charges though? Probably not. 3) The machines are all rigged in a way that I couldn't detect through spending hours wiping, using different flash cards, using different PEBs, etc and running diagnostics. This isn't super likely, but again, maybe they've changed hardware since the 2008 election.