pd, you are right. The evasion issue should be a non-starter for these guys but they hang on to it like a twig on a cliff. For pete's sake, in most instances it takes two people to evade the fair tax. If we tweak the law a bit, making a business license something more important than it is now and putting an onus on sellers that they have to check those licenses, the evasion issue will be almost moot compared to what we have now.
Ever notice how quiet they are about the illegal alien portion of the underground economy???
That's many billions of $$$ evaded right there in one fell swoop. Throw in the foreigh tourists (about 50 million in CA last year according to one article I saw), and pretty soon you have some big bux - all being evaded and/or not paid right now. It would be tax revenue under the FairTax.