CHICAGO – Former U.S. Rep. Aaron Schock asked a federal judge Thursday to throw out his corruption case, arguing that the charges are grounded on ambiguous House spending rules and that his prosecution undermines longstanding protections for members of Congress. The 2016 indictment accuses the once-rising GOP star of illegally seeking reimbursement in government funds for lavish spending, including $5,000 on a chandelier for his Washington office, which he was redecorating in the style of the “Downton Abbey” TV series. Schock’s new filing points to a host of House rules that it says are imprecise, including ones barring reimbursement for the purchase of “furniture.” The rules don’t define the word and, it says, it’s “entirely unclear whether [a chandelier] would be considered furniture.” In a filing earlier this week, prosecutors denied allegations Schock’s attorneys made in March that investigators crossed legal lines by recruiting a confidential informant from Schock’s staff.