A new statewide poll shows two-thirds of Illinois voters support Democratic Gov. J.B. Pritzker’s top policy priority, amending the state constitution to allow a graduated-rate income tax. The poll, from the Paul Simon Public Policy Institute at Southern Illinois University at Carbondale, did not ask participants specifically about the governor’s proposal. But the poll showed that a system under which higher earners are taxed at higher rates is popular throughout the state among both Democrats and independents.