Daniel, while I would accept the Flat Tax as alternative if offered, it also does not guarantee that we will not pay more in the future. Once the Fair Tax is enacted, it would be extremely difficult to bring back the income tax as it would be eliminated by constitutional amendment.
In order to bring it back, 3/4 of the states would have to agree to re-enact the federal income tax. This would be unlikely as much of the public would not stand for a repeat of the error made in enacting the 16th amendment.
The initial rate of the Fair Tax is set at 23%, in order to make it difficult to increase the amount, require 60% of both the House and Senate to increase the rate; while only a majority or 50% to decrease the rate.