It's a race to the bottom.
New Orleans, LA has a deserved reputation as a corrupt town where mob boss Carlos Marcello ran his rackets for decades with impunity. However, the good people of the Big Easy think Boston, MA should get the dubious honor as the country's most corrupt city given revelations about the dirty relationship between apprehended Irish gangster Whitey Bulger and law enforcement as reported by James Gill for The Times-Picayune:
There is no doubt that Boston had the most rotten criminal justice system imaginable and that New Orleans, for all the crimes of its Police Department, could not compare. At least our feds are not in bed with gangsters and murderers.
Nice try, New Orleans. Unfortunately, your city -- the birthplace of the Mafia in America -- still retains the corruption crown. After all, Carlos Marcello and fellow Big Easy denizens participated in the assassination of President John F. Kennedy according to the most informed authorities, and it doesn't get any worse than that.