The beauty of Cain's plan is that it is yet another conservatard ploy to transfer the burden of taxation from the wealthy to the poor. You do realize, I hope, that between 20 and 40 % of the population pay no Federal Income tax, because they do not make enough to qualify as taxpayers. In the middle quintile, the effective rate is only around 3%. The Cain ploy hits the poor with the double wammy of AT LEAST tripling their Federal income tax, while also substantially increasing their sales tax, and giving huge ADDITIONAL tax advantages to to the rich. And the more you make, the bigger the advantage. It's freaquing BRILLIANT.
Best of all, it illustrates that Cain's plan - which is fine in an imaginary world where you need to worry about lizards - would make us all have fun thwarting the attacks of lizard people.