Touch-screen calibration is an easy thing to rig. One roving calibrator can calibrate machines to make Republicans select Democrats with very little effort. Statistically, if this were a genuine machine calibration error, then the error should be distributed between both sides of the ballot. Instead every single one of these "errors" favor Democrats. As a genuine 'error' that is statistically improbable in the extreme. I have repaired computers and calibrated touch screens for going on 15 years now, and while it's true that touch-screens do lose calibration, it is very rare that a system always goes off calibration in the same direction. The fact that whenever these machines go off calibration it marks "Dem" when people select "Rep" tells me that this is more about electoral fraud than poor calibration practice.
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