I agree with the others about it being a huge drain on the poor, and likely the middle class as well, but pgardn, I'm SOOOOO glad you brought it up, because on the surface flat taxes and national sales tax seem like a good idea-- hey! Everyone pays the same!-- and it's not until people actually start discussing it that the inherent flaws in the proposed ideas come out. (and that goes for some liberal sacred cows too) As always, grateful for Derby Trail-- I get horseracing education and can talk politics, too.
By the way, I was in favor of a sales tax for a while, too, until someone pointed out to me what a burden it would be on the poor. I hadn't thought about the cost of necessities as a portion of total income until then and how taxing purchased things would necessitate more of the poor's total income going towards taxes than the wealthy's. (The guy who explained it to me, by the way, is a self-made wealthy guy who very much favors graduated income tax with the rich paying more than the poor. So, yes, he was biased, but against his own financial interests, so go figure)