[djrogers]

> That is still regressive

No, it's clearly not. Lemme give you some examples assuming a 15% flat tax and a 25K pre-bate (or credit, or whatever you want to call it):

1) 25k income, $0 tax - effective tax rate = 0% 2) 50k income, $3,750 tax - effective tax rate = 7.5% 3) 100k income, $11,250 tax - effective tax rate = 11.25% 4) 1M income, $146,250 tax - effective tax rate = 14.625%

It's clearly a progressive tax, as the rate goes up as income goes up. Feel free to call the above rates or the idea of a flat tax unfair, but please don't try to glance the meaning of well defined terms like 'regressive tax' to mean what you want them to.

[weaksauce]

There are two definitions of a regressive tax. the first deals strictly with the percentage rate and the second deals with the proportionality of effect toward lower class incomes. Your flat tax would be strictly progressive on the first front but regressive on the second even more regressive if tax deductions are still a thing. The only fair tax is one that is progressive and accounts for diminishing marginal utility of a dollar. Just like sales tax is a flat tax it's regressive because of the elasticity of demand for essentials.