The office was a year late, first offering it in July.

Roadblocks have included old technology and state data that's not compatible with what's needed to automatically register to vote: verifying a person is a U.S. citizen, 18, and has a local address.

Secretary of state officials say they were late because the law tied automatic voter registration to Illinois' implementation of REAL ID, which also lagged behind schedule. The 2005 law tightening rules for identification at airports and federal facilities requires applicants to show documents proving U.S. citizenship, making it ideal for automatic voter registration.

"We moved as quickly as the programming would allow," said Dave Druker, a spokesman for Secretary of State Jesse White. He said the stakes are too high to rush and the office wanted to ensure integrity of voter information. The agency did overhaul its opt-in voter registration system last summer under the law.

Illinois residents also can still get driver's licenses that aren't tied to REAL ID. Those people aren't automatically registered to vote, and still must "opt in" through a process that's long been offered and requires proof of age, address and attesting to the fact that one is a U.S. citizen.