In search of a revenue stream to pay for replacing the increasingly unpopular surcharge on the Michigan Business Tax, Governor Granholm last week came out in support of a more progressive, graduated rate income tax. Moving away from the state's flat tax would require a constitutional amendment, and probably a fierce battle, but it would be well worth the fight. As the ITEP Policy Brief on progressive income taxation explains, this change would add sustainability, as well as progressivity, to Michigan's tax code.