Let's take your argument to be true, just for the sake of argument.
Now let's assume that your employer makes an "honest mistake" on your paycheck...say he shorts you .005% each pay period.
That can't be a heck of a lot of money, so why not just forget it?
Unless your employer had, for example, 200 employees, and short changed each one .005% of their pay each week. Why, that employer would be getting one employee free.
But since voter fraud doesn't matter, surely you would not object to employer fraud, would you?