Rigged vote machines that recorded votes for Paul, Santorum, Gingrich, etc for Romney instead. The historical records of voting prove that by the time 30-40% of the vote is in, the candidates results typically flatline at that level. One or two anomalies could be explained, but this year it has happened over and over and is a direct correlation between the climb of Romneys numbers and the fall of the other candidates.
Notice how in most of the graphs Romney and Pauls lines are mirror images of each other. That means for every one vote they stole from Ron, the gave one to Mitt.
https://docs.google.com/file/d/0ByJAC-sfXwumZzI2bVlON2VTMnFyYVZZSnpDYnNyQQ/view?pli=1&sle=true
