Another chapter has been written in Illinois’ long, sordid history of political corruption.

Former U.S. Rep. Jesse Jackson Jr., a Chicago Democrat, pleaded guilty Wednesday to one count of conspiracy. Federal prosecutors say Jackson conspired to convert $750,000 in campaign funds to his personal use. He faces about four years in prison under a plea deal struck with prosecutors.

Caught up in the scheme was Jackson’s wife, Sandra, who pleaded guilty to filing false joint federal income tax returns from 2006 to 2011. Prosecutors say Mrs. Jackson knowingly understated the couple’s income. She faces one to two years in prison.