I'd suggest that the issue, given the concern you've got, is what is a sufficient impediment to minimize the amount of fraud that might take place? I think that is probably what the question is going to be. So how onerous do you have to make it in order to discourage fraud to the point where we feel comfortable? In a democratic society, in a free society, you allow people to misbehave to some extent.
I'd suggest this goes much further than would be required. For example, you might contemplate how many people are going to swear a declaration and risk criminal prosecution in order maybe to get away with casting a second ballot. Are we really talking about a substantial number of people? That's a significant change—