Republican presidential candidate Herman Cain said on Friday that poor Americans will not have to pay the 9 percent flat income tax under his now-famous “9-9-9” tax reform plan. During a speech in front of a vacant train depot in Detroit, the former Godfather’s Pizza CEO staunchly defended his signature tax proposal from critics who say it will raise taxes for lower-income Americans. Cain’s plan would throw out the current tax system in favor of a 9 percent corporate tax, a 9 percent income tax and a new 9 percent national sales tax. He said Friday that poor people under...