Romney's Puzzling Math—David Frum

Here's what I don't get.

Mitt Romney claims that his new proposal to reduce the top rate of federal personal income tax to 28% will not benefit the top 1%.

I’m going to limit the deductions and exemptions particularly for the higher-income folks. For high-income folks, we’re going to cut back on that, so that we ensure that the top 1 percent keeps paying the current share they’re paying and more.

How does the math on this remotely work?

Yes, I can imagine that a scale-back in the deductions for state and local taxes or mortgage interest might conceivably balance the value of the tax cut for a family at the lower edge of the top 1%. But what possible change in the deduction schedule could offset the value of a 7 point tax cut for somebody earning more than $1 million, much less more than $10 million?