Sales tax revenues are vulnerable to economic downturns. When the economy tanks, so will government revenues, at the very time you need government to provide support through the safety nets.
Income tax is much more stable and not as subject to the vagaries of consumer psychology. And there is nothing unfair about a progressive income tax as long as top rates don’t become unreasonable. Those who earn more use more services. Though there is something to be said for almost everyone paying a share no matter how small to have some ownership in the system.
If you put income tax and sales tax in, you’ll end up with both rates rising.
The problem is not the tax code. The problem is the trade agreements. Where are the tariff revenues? We’re taxing individuals 9%, and corporations 9%, how much are we taxing imports from other countries? Average tariff is 1.3%. And the consumer will pay 9% regardless of who he buys it from. So foreign competitors are at an advantage.
The rates are temporary and during that time will require 2/3 majority to change.
999 is just phase one bridge to the Fair Tax. http://www.fairtax.org is packed with information and answers to most sales tax questions.