Republican presidential hopeful Herman Cain’s 9-9-9 tax plan has been both a boon and a burden. On one hand, it has helped him vault to the top of several polls, but it also has attracted a lot of criticism from both the left and the right, in part because it would force poor people to pay higher taxes. Speaking before a crowd in front of the Michigan Central Station, a dilapidated former Amtrak station, during a campaign stop in Detroit on Friday, Cain announced a plan for that: 9-0-9.

“If you are at or below the poverty level, your plan isn’t 9-9-9. It’s 9-0-9,” he said. “Say, amen, y’all. If you are at or below the poverty level based upon family size … then you don’t pay that middle 9” individual flat tax.

Cain insisted that the provision was always part of the plan, but his opponents didn’t “didn’t get to” it when the read it.

During the first several minutes of the CNN Western Republican presidential debate that Cain and his rivals participated in earlier this week, the plan, which includes a flat nine percent tax rate for individuals and businesses, and a nine percent national sales tax, was judged very harshly because low- and middle-income households would pay higher and in some states, additional taxes, while the wealthy would pay less. In addition, the Tax Policy Center said that Cain’s plan would impose a tax increase on 84 percent of U.S. households. It has not yet done an analysis of 9-0-9.

Cain’s tweaked proposal also calls for the creation of “opportunity zones” in depressed cities, which would allow businesses in those areas to exempt their payroll and people who live and work in the zones also would also get tax breaks. A brochure explaining the proposal, which Cain also says has always been a component of his 9-9-9 plan, says that the zones will be able to identify “barriers” holding back entrepreneurs, such as building codes, zoning laws and minimum wage laws.

“Bottom line, folks: 9-9-9 means jobs, jobs, jobs,” Cain said.

But Richard Trumpka, president of the A.F.L.-C.I.O., told Fox News that Cain’s plan would adversely affect organized labor.

“To have Herman Cain, a serious contender on the Republican side, to make a statement like that, that he wants to further lower wages, that he wants to do away with the minimum wage – it’s almost laughable,” Trumpka said.

(Photo: Bill Pugliano/Getty Images)