High Quality Content by WIKIPEDIA articles! The 9–9–9 Plan, a centerpiece of Herman Cain`s 2012 campaign for the Republican Party`s nomination for president of the United States, was introduced in August 2011. The 9-9-9 plan would replace all current taxes (including the payroll tax, capital gains tax, and the estate tax) with 9% business transaction tax, 9% personal income tax, and a 9% federal sales tax.