Hunter Biden says it’s unheard of for anyone to be charged with gun crimes for the kind of behavior he engaged in. Tell that to David Jon Ray, an Illinois businessman who failed to pay taxes over three years and, when authorities moved to investigate him, admitted he was a habitual cocaine user with a penchant for guns. He earned a 37-month federal prison sentence for those offenses. Mr. Biden, who also faces a battery of tax and gun possession charges, goes on trial in a federal court...