I disagree with the papers assumptions using current GDP. The GDP will increase dramatically with the elimination of most taxes on manufacturing and business, therefore decreasing the necessary tax rate to a much more conservative number. I may have quoted too low, but I think it is feasible given the offsets that a drastic downsizing in the Federal Government that should result. Many programs that are funded by Federal dollars could be shifted to the states for funding and thus further decreasing the size and expenditures of the federal government. Tops on my list would include The Department of Education, The Federal Housing and Human Services Agency, many agencies within the Treasury, etc. I think you get my drift. The Feds are bloated and dipping their wicks into areas best left to the States. And when the country and the Federalist Republicans and Democrats come to their senses, it just might happen.
And you're correct about the revenue shifting, too, I think. The fly in the ointment is geting the Feds to do it, but with a new, decent tax system - who knows. Perhaps they'll begin to look at reason (finally).
I sure hope so.