There are a number of myths that I continuously hear repeatedly on the right. One is that federal taxation is exceptionally progressive. I've shown before that it isn't. It's progressive, but mildly so. Here's a chart that contrasts share of income with share of tax burden by income group when you consider all taxes, including state and local. (Italicized portion added per DF's comments below, sorry for my poor writing).
Another claim is that the Bush tax cuts lead to an increase in federal revenue. Here's the data. Bush is the first President since Eisenhower to preside over an administration that actually saw a reduction in revenue. The Bush reduction was even greater than Eisenhower, making Bush the worst performer by this measure.
I've made these points before, but what I want to add here is information about how the tax code has become much less progressive over the last few decades for the highest income groups. Looking at my prior link you can see that tax receipts as a % of GDP are not a lot different over the last few decades. On the order of 17 or 18% of GDP typically. While that has remained fairly constant, what's changed is that the burden of those receipts is falling more and more to the poor.
Most people know that the tax rates for the upper income brackets were enormous. The top marginal rate was something like 91% at one point. But what was the effective rate? Tax havens and shelters play a role. How much of a role? Piketty and Saez have the data in detail here. A chart derived from this data is below: