IIRC, about half the middle-class is black. But middle-class has a broad definition and may include a high percentage of people below the personal income tax threshold. But don't forget VAT.  Poor people have a pretty high VAT burden relative to income, even after allowing for VAT-exempt staples.

So I may be wrong on the personal income tax side (maybe half or less of the tax burden is black) but my point was more that all taxpayers are being screwed.