You can change your vote in private. If you're worried about getting locked up and/or murdered by your wife after she has seen who you initially voted for, then you could set up a cron job to change the vote even if you're no longer breathing.
In addition, the same problem applies to paper voting. What stops your wife from demanding that you wear a hidden live streaming camera when you go to vote, so that she can see you really cast your paper vote for the candidate she insists on?
In addition, the same problem applies to paper voting. What stops your wife from demanding that you wear a hidden live streaming camera when you go to vote, so that she can see you really cast your paper vote for the candidate she insists on?