Good point, except that this government has routinely ignored — hell, trampled on — the Constitution for at least 7 decades. The Constitution won’t stop this lunatic and mendacious scheme, unfortunately; it’ll have to die under the weight of its own dishonesty.
Why don't you point-by-point tell us exactly what makes the Fair Tax proposal and "lunatic and mendacious scheme" -- labeling each point which it is, lunatic or mendacious?