The Heritage Foundation has a pretty good article regarding the supposed tax burden shifting to the middle class. This pretty much sums it up:
Now let’s look at the middle 20 percent of earners. In 2004, they would have paid 10.4 percent of federal taxes without the Bush cuts. With the cuts, they will pay 10.5 percent of federal taxes. Note, however, that because of the cuts, the federal tax burden for the middle 20 percent of earners dropped from 16.5 percent to 14.6 percent. In other words, these earners are paying a slight bit more of federal taxes, but a lot less in federal taxes. In other words, their taxes were cut.
The HF have a link to a PDF that lays it all out.
