A single tax rate that applies to everyone obligated to pay the tax. Sales taxes are flat taxes. There have been proposals to substitute a flat tax on income for the current graduated tax, which taxes higher incomes at a higher rate. Proponents argue that the flat tax is fair and simple. Opponents view it as a bonanza for the wealthy.
This week sometime, Rick Perry is going to announce the details of his plan for a flat tax.
The Romney is singled out as one of the only candidates without a flat tax proposal.
There is also his fiscal policy of a flat tax, which will never be received well by the overall population.