In a preview of what is being billed as a major economic speech in Detroit later this week, Mitt Romney doubled down on his economic proposals Wednesday.

Standing before a large and boisterous crowd in Chandler, Ariz., Romney promised to make the tax system "simpler, flatter, and fairer," by reducing individual rates by 20 percent across the board. If implemented, the top rate would drop from 35 percent to 28 percent, the same top rate Americans paid under President Reagan in 1986.

To prevent an increase in the federal deficit by lower tax receipts, Romney said he would limit deductions and exemptions for higher-income brackets, saving the burden from falling on the middle class.

"I want to make sure that you understand for middle-income families, the deductibility of home mortgage interest and charitable contributions -- those things will continue," Romney said to loud cheers. "But for high-income folks, we're going to cut back on that, so that we make sure the top 1 percent keeps paying the current share they're paying or more. We want middle-income Americans to be the place we focus our help, because it's middle-income Americans that have been hurt by this Obama economy." (read more)