Steve Forbes has been yacking for years on a Flat Tax, even he knows that can't happen unless you change the apportionment provisions of the Constitution, Article 1 Section 2 Clause 3. Even though the Income Tax and the Withholding Tax are direct unapportioned taxes going directly against the Constitution. The only "fair tax" (that's an oxymoron if there ever was one) would be a Consumption Tax. It's voluntary, unapportioned and all those people who work off the books would pay it when consuming.
All I Really Need to know I learned in kindergarten
I was taught in kindergarten that if you give something to somebody you have to give it to everybody. I wouldn't care why they were getting a piece of gum as long as I was getting a piece.