Herman Cain’s “9-9-9” plan, according to this article, would almost double the taxes of an average family of four (who bring in just under $50,000 annually). And it might be considerably more than that. Most of this is from the new national sales tax he wants.
In short, it would reduce the income tax requirement for people who do pay income tax, but the sales tax element of it is added to your expenses. If you are one of those who pay below a certain threshold, or perhaps pay no income tax at all (say, a retired person whose income level is low enough that they pay no income tax), then the sales tax is not offset by the reduction in income tax – for you.
Herman Cain is now committed to this. He can’t change it without admitting that it has problems. So, that’s a serious problem. I hope he’s got the gumption to do the right thing on this, fess up to it, and fix it before it goes too far. Preferably now, but especially if he gets elected. There isn’t much worse than a person in power, who has discovered something wrong, but who cannot fix it because it would hurt his political image (or his pride).
Besides that, his plan may be unconstitutional; the 16th amendment gives the congress power to tax income, but not sales.
Frankly, I’m not an expert; is the article wrong in its assertions? I recon  a lot of people would like to know.
One thing this teaches us, though; any major change to the tax laws, badly as we need them, is going to help some people and punish others. I would certainly personally like to see a simple, equitable tax law that is fair to everyone and doesn’t take a computer program or a highly trained expert to figure out; possibly the Fair Tax is a candidate.
 recon : possibly obsolete usage – means “I think” or “I estimate” or “I calculate”. May be colloquial to East Texas in this usage, I learned it from my grandfather.