Sorry, but this is something the "poor" are paying less and less of each year. I, like MATT, despise the income tax, and I know that the $6,000/yr number is incorrect. While my wife and I were in school, we made a little over $18,000, and with the "earned income credit" due to our son, we received all plus more back. This is very common in the "poor" who statistically have more children than the more affluent. Not to mention each election passes with the politicians pandering to this group telling them about all the tax benefits that they will provide if put in office.
This is not a significant barrier to people bringing themselves up from "poverty", it is only a wall that prevents one from keeping what they earn.