The flat tax is still a likely rabbit-in-the-hat trick for McCain. We need to have a good alternative at the ready.
Here is a plan that would establish more fairness without necessitating any significant process or ideology changes:
Tag for sunset all tax deductions and credits that effect fewer than X% of filers. I would propose 0.1% (one out of a thousand) but even one out of ten-thousand would have an effect.
A deduction or credit that benefits less than one out of 1000 taxpayers would be, by my book, easy to classify as "unfair." The IRS could list all of those items tagged for sunset in a public list (online of course), and perhaps a super-majority of Congress might be allowed for an override.
The benefits? Millions (billions?) of dollars of "free money" that is currently unfairly distributed, usually in long-forgotten perquisites that clog up the tax rules many years later and make life for the rest of 1040 filers miserable as they work through calculations for deductions for which they will not benefit.
We could also get back, as a result, to a cleaner, modestly progressive tax system.