Cain would not try it without GOP majorities in both houses of Congress, to avoid perverting the plan. The 9% is “on top of” a much smaller income tax. The old, large income tax appears right now in the prices of goods and services.
It looks to me like he 9-9-9 is never going to happen without a Republican majority in both Houses, so that is a big if, and what if We get a Dem majority in 10 years?
We would need a Constitutional Amendment to keep the tax plan at 9-9-9. It will never happen because we can't even get a balanced budget amendment passed.
So Cain's tax plan is nothing at all, never will pass and can only be torn down for it's faults. So we go on to his border plan, 2000 miles of electrified fencing with enough voltage to kill anyone who touches it. How far is that gonna go in a general election?