It's a straightforward examination of how their oversimplified, snake-oil panacea actually works.
All consumption taxes, including sales taxes, discourage consumption.
And the burden of taxation will fall most heavily on those on the lower rungs of the economic ladder because they must devote a larger proportion of their earnings to purchasing "necessities" (food, clothing, shelter, medicines). The so-called "fair tax" falsely promises to remedy this inherent burden by entrapping them in cradle-to-grave "tax rebates" from the Social Security Administration.