There is even more insidious possibility. Even if the screen shows you are voting for Romney, inside the black box the vote is added to Obama. You can’t see it because it is not displayed on any screen.
That is why I am in favor of a paper record printed of each vote. The machine dispenses the printed paper to you, you look at it and then deposit it into a ballot box. Note that it is a computer generated paper ballot, and it will have none of the problems associated with hand marked ballots, in counting the votes through a scanner.
Now a permanent paper record exists for later verification in case problems or questions arise.
Would that be possible?
Our machines have a card like a debit card.
You poke it in the machine, cast your votes and the machine spits the card out and a poll worker puts in a box.
Are the votes tallied on the cards?
[since I’m in the gimme state of MD it’s a moot point but still...]