Perry's tax plan miracle

Put simply:

The plan starts with giving Americans a choice between a new, flat tax rate of 20% or their current income tax rate. The new flat tax preserves mortgage interest, charitable and state and local tax exemptions for families earning less than $500,000 annually, and it increases the standard deduction to $12,500 for individuals and dependents.

I'm mildly impressed, but Kevin Drum, predictably, is profoundly unimpressed:

Can we please spare a moment for the people who are really going to suffer because of this? Yes, I'm talking about whichever poor schlubs at the Tax Policy Center draw the short straw and have to go through the dreary motions of scoring this. We all know the basic answer, of course: Perry's plan represents a massive tax cut for the rich and a huge loss of revenue for the federal government.