I'm sooooo fearful of having BOTH an nrst and an income tax simultaneously.
Since the repeal of 16th takes time, I thing the nrst's [fairtax] approach is best - it erases the income tax code. Poof - it's gone. Although it could be re-written, it would take a long while to negotiate it all. It would take even longer with Tea Party congress critters. That would give us time to get the amendment through. Hopefully with a repub house, senate, and white house.
I still don't know why Cain deviated from the straight Fair Tax plan. I fully support the Fair tax as our least bad taxing plan.
An issue with FairTax is how to transfer that 23% tax from every retailer in the USA back to the Federal government. That means a massively-upgraded monetary transaction network and upgraded communications networks, and it may take a couple of years to set up every retailer to make it easy to transfer the tax collected.