If you're like 95% of all Americans, you can't afford a flat tax. A flat rate tax would have to be assessed at at least 25% on all income with no exemptions, credits, or deductions at all. Only the wealthiest taxpayers pay a net rate even close to that.
Political "compromise" has backed us into the position that a flat tax would be impossible without changes that business would not stand for and probably could not afford. In the early 1960s it was possible to support a family of 4 on the $1.40 minimum wage. Had the minimum wage kept pace with inflation, it would be around $14 an hour or even higher. Interestingly enough, it would take about $28,000 a year to support that same family of four to the same standard as in 1965 on $2,800.
Why did the minimum wage shrink so badly? No surprise that "conservatives" wanted nothing to do with allowing it to rise, so they offered the Earned Income Credit as a way to help the lowest of earners scratch out an existence. The Child Tax Credit and Additional Child Tax Credit were offered up under the guise of "compassionate conservatism" in order to maintain an artificially low minimum wage. Like a band of idiots, everyone else went along with the idea.
Fast forward to 2010 and consider the plight of the single mom supporting 3 kids on a crap $9 an hour McJob. Switching to a flat 25% tax would cost her $7,984 in refundable credits which bring her within striking distance of the poverty level in most of the US. Actually, they're about $2,000 short, but she manages to get by on lots of white-box mac & cheese. Tack on a $4,500 tax bill and her cash flow crashes by $12,484. Within weeks, she and her kids are on the streets or in a shelter and probably on welfare. Mind you, she's not some lazy bum as she's working full time but basic survival is now impossible.
Or consider the typical family of 4 earning the $46k median family income. They get by OK, though not much in the way of extravagances. Might even own a home in a lower cost area. They don't pay any Federal income tax to speak of, about $160 a year. A 25% tax burden and the loss of the Child Tax Credit would cost them $11,500 a year. That leaves them only slightly better off that the single mom is today. Home ownership is out of the question and they rent in one of the harsher neighborhoods.
On the other hand, a fat-cat $10 million a year CEO (who probalby helped contribute the economic meltdown through unbridled greed) gets a cool $1 million a year cut in his taxes. How much of that do you think he'll share with out single mom or family of four? You damned well know the answer to that: $0.00.
So you tell me, Sparky, which is more fair to society taken as a whole?? The irresponsible tax cuts and runaway spending over the past decade has quadrupled the deficit and driven poverty up by 20%. The wealthiest 2% of taxpayers saw their discretionary income nearly double, while the middle class got comparative crumbs at about 6% growth. I have not seen a single one of those billionaires do a damned thing to create new jobs for anyone but a few stockbrokers and investment bankers.
Lastly, if you consider tax burden as a factor of the amount of wealth controlled, the top 2% of all earners in the country pay about HALF of their "fair share." The fact that they pay in more dollars than someone at the median income is utterly irrelevant.