[OHelix]

I'm sure there could be some issues there, but at present I think that would be a good thing. I don't know how you could prove you had the money and that it was after tax, as opposed to borrowed money. I would think that would be necesary or people would borrow money and claim it was after-tax to apply for the credit, or even claim money they did not really have. I wonder if it was already considered and dismissed for some reason... even if just simplicity.

[BikerNYC]

I wonder if it was already considered and dismissed for some reason...

It may have been, because with a large budget deficit switching over from one kind of tax to another and double taxing certain money during the transition would be a huge windfall for the government.