I have to admit I am not 100% clear on his plan. I've read that it's a flat tax, a vat tax, now a national (consumption) tax.
You're correct though, if we don't repeal the 16th, we'll end up with all the above.
I know one thing though, congress will never give up their ability to tax, it's where they derive their power.
Its not really a vat, that has been an attack on it.