Both person A and B pay one federal tax on each dollar of their earnings. The one who works subsidizes the one who doesn't have to. Substantially. We punish work if you believe that the cost of being a citizen of a successful country is punishment.
There is no tax tactic more regressive than the flat tax. It would take about one generation to turn us into a dysfunctional banana republic aristocracy.
Why?
Good question.
The flat tax has worked in other countries there is no reason it wouldn't work here.
The crybaby argument is that since the so called poor ( you know the almost 50% of Americans who don't have to pay income tax) would finally have to pay something it would ruin them.
I prefer to believe it would encourage them to work an extra % a week to cover the taxes, give them a true feeling of ownership regarding the spending of the country and a real reason to agree government should be fiscally responsible with OUR money.