http://www.dailykos.com/story/2013/05/14/1209013/-Why-a-Flat-Rate-Tax-is-Unfair-A-Quick-Overview-of-America-s-Wealth-Inequality-and-Tax-Structure#comments The Daily Kos gives some reasons, but misses the main point. The one thing people seem to ignore or not mention or think about is who benefits from taxes...The poor and the working class don't have much at stake. Roads, military, education, transportation, the legal system, healthcare, banking and the monetary system, almost everything is geared towards making the comfortable more comfortable, the wealthy more wealthy, the powerful more powerful. If you shift the tax burden to those who have less, which a flat tax does, you make them pay more for the benefit, comfort, wealth, and power of the rich. You make us BUY the services for them.