Can't really comment on the tax code specifics of the US but I know of a general rule that applies everywhere you go. The middle class burdens all the public spending there is through taxes. The poor are generally consumers of public spending (this can be argued at length but generally the programs that are financed through public spending is meand foremost for the underprivilaged, although there are many exceptions that can be cited), the middle class fund this spending through taxation, while the wealthy usually finance public spending through government debt financing (ie. they buy the government dept secuirities and make profit off of public spending).

That unfortunately has been the way it is (except for the bit about the poor) for ages........