ACA: Is the Mandate a Voluntary Tax or a Voluntary Penalty
It really doesn't matter what you call it, but the key here is that it is "voluntary".
We should explain that fact every time we describe it. If you choose not to carry insurance, and can afford to buy it, you will be charged a fee (or penalty or tax) at a rate of about $840 a year. But it is not a fee (or penalty or tax) on everyone, or even anyone.
I am for a single payer, government option rather than this "Republican" idea of a mandate. But I know how politics works and Obama had to move to the center on this to get his "blue dog" Democrats on board to get this thing to pass. I would have rather had lost the vote on principal than won with this mandate. But, as the President says, let's not re-fight this battle. It is what it is and that's a step in the right direction.
But the fact remains that the mandate, if phrased as a tax, is strictly voluntary. You don't have to pay it, if you comply with the law, just as I don't have to pay a ticket if I choose not to speed when I drive.