Herman Cain is now considered a front-runner in the race for the Republican nomination. Mr. Cain’s meteoric rise in the polls has been driven by his proposed 9-9-9 tax plan, which would scrap the current tax code in favor of a 9% flat tax on personal income, sales, and “business income.” Mr. Cain is to be commended for trying to drastically reform the tax code, but his plan presents an unending list of problems.