DuPage County Republican chairman and state Rep. Randy Ramey was charged Sunday with driving under the influence of alcohol.
Ramey, of Carol Stream, took responsibility in a statement.
"On Sunday morning I was issued a citation by the Carol Stream Police Department for driving under the influence of alcohol," Ramey said in the statement. "I regret and take full responsibility for my actions, and I am prepared to face the consequences. I am deeply sorry to disappoint my family and my constituents."
Carol Stream Police Chief Kevin Orr said Ramey was stopped at 2:10 a.m. Sunday because "he was basically crossing over the centerline on Lies Road" near Bedford Drive.
Orr said Ramey failed four field sobriety tests, before being taken to the police station, where a breath test recorded a .179 percent blood-alcohol concentration, more than twice the legal threshold.
Ramey was also charged with improper lane usage. His next court date is Sept. 26, Orr said.
Ramey, 48, was alone at the time, said House Republican spokeswoman Vicki Crawford.
He was voted to take the helm of the county party in late July, succeeding DuPage County Board Chairman Dan Cronin. Ramey is the stepson of former GOP Senate President Pate Philip and has garnered attention in Springfield for proposing Arizona-style immigration laws for Illinois.
He has served in the Illinois House since 2005 and hasn't yet announced his election plans for 2012.
In 2006, Ramey sponsored legislation that would allow local police to use DUI fines to buy equipment that helps prevent alcohol crimes.