DeMint on MTP this morning said (roughly) "I would not support any plan that raised taxes on any American" regarding his national sales tax plan.
So, he's managed to construct a radical overhaul of the entire tax system which is both revenue neutral and ensures that not a single American would pay higher taxes.
That's a neat trick. It's so neat that one wonders what the point is, if every single individual's total tax burden will remain precisely the same.