Pure smoke - pure mirrow. The tax loopholes are eliminated in a national sales tax and there are no exceptions to the sales. Flat tax or NST either one would eliminate the volums of federal code we currently labor under.
However, with a flat tax, there is always a company that will rent a politician to get a law passed making THEM exempt for paying it. If the tax is on the end user of the item, then EVERYONE pays the tax, no exceptions.