That's why they keep on punting when asked to do the math on their tax plan:
And the math would be different if Romney's plan proposed eliminating more than $165 billion in loopholes and deductions on those very same taxpayers, but it doesn't—because it can't.
So what you have is a scenario where Mitt Romney is calling for a $251 billion annual tax cut (in 2015 dollars) for the highest income earners and even if he eliminated every conceivable tax break for those very same people, he'd only raise $165 billion—leaving him with an $86 billion hole.
Unless Romney reduces the size of his proposed tax cut for top earners (which Paul Ryan has ruled out) or decides to explode the deficit, under his plan the middle class will shoulder a great share of the tax burden. It's just math—it's really that simple.
Now, that didn't take long, did it?