Reminds me of the time I worked the polls in 2004 in NC, which was (maybe still is) using electronic touchscreen voting. I clearly remember an elderly woman with very poor fine motor control. Her hand was shaking terribly. I watched her hit the "next" button and, due to the shaking, press it multiple times and skip most of the ballot.

I asked her if she wanted my help to go back and finish her ballot. She declined, saying she'd managed the vote for President and that was all she really cared about.