No one would invent our system if working from a blank slate. But, a couple of things come to mind that argue in favor of tinkering with the system we have, rather than starting over. First, the political problem. Every little crazy bit of the IRS code has a constituency behind it that thinks it is a great idea. Will we all be willing to give up our little prize for the greater good? While any new system can be made revenue neutral overall, there will be winners and losers. There is every reason to think that a national sales tax will include favorable treatment for favored interest groups. I can hear the candidates now: "I will never sign a tax bill that interferes with your rights under the second amendment" or "Taxing abortions violates a woman's right to choose" and so on.

Second. A lot of people have invested a lot of money in reliance on the existing Code. What happens to the guy who today bought a 30 year tax free municipal bond, paying 3.5% interest? Without the tax benefit that gives it a premium in value over a taxable bond paying the same rate, the muni will be worth less. We are talking about $ trillions in bonds, so the dollars are significant. People buy homes in reliance on the mortgage interest deduction.

All this talk about making taxes simple is misplaced. Most of us already have simple returns. Most of the thousands of pages of the tax code don't apply to working stiffs.