So who are the extra people who get taxed under the fair tax? Given that the rich already pay more than their fair share, who are you adding to the tax rolls?
Anyway, the only people who pay all their taxes now are those who have taxable [legal] "income". But there are zillions of people who don't have legal "income" but do spend. That is, there are far, far more people who spend than people who have taxable income.
In your terms, I'm adding to the tax rolls anyone who does not pay income and payroll taxes now. BTW those of us who ARE paying income/payroll now will get a reduction :)