A lot of people asked that question about the lever machines when they were confronted with the huge expense and lack of accountability of the electronics. They were claimed not to meet HAVA - the Help ('Hack') America Vote Act - if I recall correctly, because of a lack of a paper printout. The corrupt Democrats of the Rendell mob made paper printouts from the electronics 'illegal' in PA, which is a more demonstrable violation of HAVA. Those crooks have been violating PA law all along. They even started refusing perfectly legal elector demands that the systems be examined by independent experts.
How hard could it be to add a paper printout capability? But that's not the question. What is the question, as you're pointing out, is how best for the RATS to rig elections. Disgusting.