Florida: A Comparison of Op-Scan voting results and E-Touchscreen results in the 2004 Presidential Election, in counties that had between 80,000 and 500,000 voters.
The counties that used optical scanner machines to record votes showed a consistent pattern of far more votes for Bush and far less votes for Kerry than projected, based on the number of registered republicans and democrats. (Data for this and the next chart from http://ustogether.org/Florida_Election.htm.)
The counties in Florida that used touchscreen voting had a relatively normal distribution of final votes for Bush and Kerry compared to the amount of registered democrats and republicans and the projected turnout.
