State and local governments have figured out that the rich are geographically mobile and financially able to decrease their taxable activities, so raising taxes on the rich will not generate more revenue (see Kah-lee-fornia). Obama hasn't figured this out yet, but the 2011-2012 revenue figures will give him a clue.
The poor, on the other hand, are screwed. You can tax the crap out of them and it only makes them poorer and less able to get away from the taxes. Phoenix is going to implement a food tax. SF Muni is raising fares three times in a row. How many poor people in Phoenix can escape to a better place? How many Muni riders can really telecommute or buy, maintain, fuel, and park a car instead?
Europe had this figured out a long time ago. Instead of getting so much of their revenue from high marginal personal and corporate income taxes, they have VAT (sales) taxes that keep the poor poor and keep revenue rolling in to feed the government beast.