Proposes to amend the Revenue Article of the Illinois Constitution. Removes a provision that provides that a tax on income shall be measured at a non-graduated rate. Provides that there may be one tax on the income of individuals and corporations (currently, there may be no more than one income tax imposed on individuals and one income tax imposed on corporations, and the rate of tax imposed upon corporations shall not exceed the rate imposed on individuals by more than a ratio of 8 to 5). Provides that the income tax may be a fair tax where lower rates apply to lower income levels and higher rates apply to higher income levels. Provides that no government other than the State may impose a tax on or measured by income. Effective upon being declared adopted.