Look at it this way:
If you take your money out of savings and spend it right now you will be paying what amounts to another tax - a "hidden tax" in the form of prices that are articially raised by the effect of having income taxes embedded in them.
With the FairTax you have the benefits of controlling your consumption and not all things are taxes - used things for example are not taxed. You can't control this typically with some types of withdrawals presently since they will be taxed when withdrawn. In addition, investments are not taxed under the Fairtax so you have a better opportunity to climb up a few rungs on the economic ladder.
Sure, but then that tax will just become 'unhidden' under the fair tax.
So $1.00 in savings (post tax money) buys the same as $1.00 in newly earned money (pretaxed money). Any way you cut it, my $1 in savings absorbed an income tax hit that the new $1 earned does not.
So for money I saved and paid 33% in income taxes, I earned $ 1.50 pretax and kept $1.00 post-tax, and that has $1 in buying power under the fair tax system. Under the fair tax, I earn $1.50 and keep $1.50, which has $1.50 in buying piower under the fair tax system.
The Feds are clearly taking a second tax bite out of my saved $1.00 when I try to spend it under the Fair Tax system, see?