As the long as the Income Tax (sic) is enshrined in the Bill of Rights..(now there is a chuckle worthy topic) then any law imposing the Fair Tax can be coupled with increased income (sic) taxes, there is no getting around that fact.
And that differs from the current system, how, exactly? Congress can raise the income tax rates anytime it cares to and we are virtually powerless to resist. Not so with consumption based taxes.
From Federalist No. 21:
“...It is a signal advantage of taxes on articles of consumption, that they contain in their own nature a security against excess. They prescribe their own limit; which cannot be exceeded without defeating the end proposed, that is, an extension of the revenue. When applied to this object, the saying is as just as it is witty, that, ``in political arithmetic, two and two do not always make four.’’
If duties are too high, they lessen the consumption; the collection is eluded; and the product to the treasury is not so great as when they are confined within proper and moderate bounds. This forms a complete barrier against any material oppression of the citizens by taxes of this class, and is itself a natural limitation of the power of imposing them.
Impositions of this kind usually fall under the denomination of indirect taxes, and must for a long time constitute the chief part of the revenue raised in this country....”