Good news today from Illinois, where a federal appeals court has overturned a lower court ruling that blocked large counties from allowing their residents to register and vote on the same day.

The Seventh Circuit Court of Appeals found no evidence that Illinois’ same day registration law discriminates against residents of less populous counties. Patrick Harlan, a Republican candidate in the state’s 17^th Congressional District, argued that the law works to boost Democratic Party registration and disadvantages Republicans.

Common Cause had filed a friend of the court brief in support of same day registration.

The Illinois law requires counties with more than 100,000 residents to offer same day registration; smaller counties are permitted but not compelled to do the same. Only 20 counties exceed the 100,000 resident threshold but they are home to 84 percent of Illinois residents.

Harlan argued that because Democratic voters tend to dominate in cities and Republican strength is in suburban and rural areas, the law gives Democrats an unfair advantage in signing up voters.

But the appeals court said research by a political scientist whose work was the basis of Harlan’s case “comes nowhere close to demonstrating that Illinois voters would suffer any harm at all – let alone irreparable harm” under the law.”