Rick Perry says he'll propose a flat tax

The flat tax has been an elusive dream of conservative Republicans for decades.

In a speech before the Western Republican Leadership Conference in Las Vegas, Perry previewed the broad outlines of a tax plan that he said he will soon present. Among its features, he promised, will be spending cuts, entitlement reform and a flat tax.

What is a flat tax? Just what it sounds like: One tax rate for all Americans. Right now, income taxes are progressive, with the rate increasing with each income bracket. A flat tax would mean an end to complicated forms, itemized deductions, credits and other loopholes.

Most flat-tax plans still have some deductions, however. For individuals, there's a deduction based on family size. For businesses, there's a deduction for wages and other costs. After those deductions, everyone would pay the same rate.