Who pays taxes? From Spread Your Own Wealth Around at Powerline:
According to the most recent (2006) data released by the IRS, the top 1 percent of filers paid nearly 40 percent of all income taxes; the top 5 percent paid 60 percent of all income taxes. The bottom 50 percent paid virtually no income taxes (3 percent of all income taxes paid).
The personal income tax, the federal government's main source of revenue, is collected overwhelmingly from a relative handful of Americans. The large majority of all Americans pay little or no income tax.
Given that poorer citizens always outnumber the rich, political philosophers have long worried that government based on majority rule could lead to organized theft from the wealthy by the democratic masses. "If the majority distributes among itself the things of a minority, it is evident that it will destroy the city," warns Aristotle.
We have turned into a two-class society: the shrinking paying class and the large receiving class. Disgruntlement ensues, because the paying class resents carrying everybody else's load, and the receiving class covers up their embarassment and shame about receiving with resentment, envy, and a trumped-up sense of entitlement: it is basic human psychology that the recipient always must resent their benefactor who, in politics, is their neighbor and compatriot.
The obvious political strategy is to increase the % that pay no taxes (or, under Obama's plan, get "refund" checks without paying taxes, aka welfare, aka vote-buying), while raising the numbers of government employees in any way you can. That's how you create a "grateful" population of spirit-crippled dependents, incentivized to work the system and to vote to their economic advantage. Obama's plan will take from the middle class and the small number of wealthy while bringing the number of non-taxpayers up to the magic number of 50%.
100 economists say it's a disastrous idea, and so do I. I believe that everybody should pay their dues so as to feel like a part of the country by contributing their sweat and to have a stake in it, but with 50% of people paying no taxes and getting checks instead, you'll never get a flat tax through. The receiving class would rebel.
The now-famous Joe the Plumber understands life better than any Dem politician, latte liberal, or academic, because he is in real life and he made it work.