Please feel free to provide this data and present the analysis.  I am not sidestepping anything, I'm simply commenting on data I have seen which presents Federal income taxes and income broken into various income categories.

I would like to see different data included as well:
-social security and medicare, as you suggest
-total income rather than adjusted gross income since some income levels are eligible for personal deductions, child care deductions, supplement to income with the "earned tax credit", and other income levels are not.
-state and local income taxes
-property taxes
-cigarette and alcohol taxes
-gasoline taxes
-sales taxes
-and the myriad of other taxes which have different effects on different levels of income

If you could find that data, link us all to it, and provide analysis,,,I would be very interested as I'm sure others would.