The side effect of Herman Cain's poll surge: Actual media scrutiny about his 9-9-9 tax plan. ThinkProgress makes the obvious but needed point about the impact of "broadening the base." Citing CAP's Michael Linden:
[S]omeone in the bottom quintile of earners — who currently pays about 2 percent of his or her income in federal taxes — would pay about 18 percent under Cain’s plan (9 percent on every dollar they make, plus 9 percent on every dollar they spent, which would likely be close to all of them). A middle-class individual would see his or her taxes go from about 14 percent to about 18 percent. But someone in the richest one percent of Americans would see his or her tax rate fall from about 28 percent to about 11 percent.
Steven Sloan wonks out even further.
Using 2010 figures, Cain’s plan would have collected $922.1 billion in revenue from the national sales tax with no exemptions, $912.7 billion at a 9 percent individual income tax with few deductions or other tax benefits, and $127.7 billion from a 9 percent tax on U.S. corporate income with no deductions.
The federal government in 2010 actually collected $898.5 billion from individuals, including levies on capital gains; $191.4 billion from the corporate income tax; $864.8 billion from Social Security and retirement taxes; $141 billion in other taxes, such as estate and gift taxes; and $66 billion in excise taxes. This doesn’t include the taxes levied by states on retail sales and property.
Id est, Cain's tax plan raises slightly less revenue. That's a feature, not a bug, for a Republican primary. In other races, backers of national consumption taxes get whacked for stuff like this. But the one time 9-9-9 came up in a Republican debate, Mitt Romney was careful not to dismiss the possibilities of a "Fair Tax" style replacement of the income tax.