Every national election about 3.5 million votes are never counted- they are termed "spoiled" and thrown into the garbage. Machines can't determine what these ballots indicate, but if human counters are given a chance, usually they can determine the intention of the voter. Another 2 million non-votes occur every election cycle- these are the votes that were never allowed to happen, when people are mistakenly kept from casting their ballot due to paperwork/computer errors.