Flat Tax

What's with the Republican love of the "Flat Tax" ?

Perry Proposes 20 Percent Flat Tax. Perry would keep popular deductions for mortgage interest and charitable gifts.

Other Republicans/Conservatives have embraced the Flat Tax as well. Why? I think Perry's plan is dunderheaded. Keeping those deductions and making the tax flat is just the opposite of what I would like to see. It makes much more sense to me to eliminate as many deductions and loopholes as possible, thus simplifying our tax system, and reducing economic distortions.

I really don't have much problem with a progressive tax rate structure, and it seems a majority of "rich" people don't either. Should I pay a higher rate than someone who makes half what I do? Yes.

Is it so difficult to look up your total tax in a table? Is it that really complicated? More complicated than multiplying by 20%? No.

As I said, I don't get it.