CLEVELAND — The government has asked a judge to stick with a decision denying convicted Nazi war criminal John Demjanjuk a chance to regain his U.S. citizenship, arguing that the retired autoworker is just trying to drag out the case. Demjanjuk’s appeal for reconsideration “rehashes old arguments” and “is nothing more than an effort to prolong this litigation by any means necessary,” the government said in a filing Thursday night in U.S. District Court. Demjanjuk, 91, who lived for many years in Seven Hills in suburban Cleveland, was convicted by a German court on more than 28,000 counts of accessory to murder. The court found he had worked as a guard at the Sobibor death camp in Nazi-occupied Poland.