Sonny Blue is the Racket Boss of the protection racket in Pointe Verdun, running it for Roman Barbieri. He's a Grade-A psycho and one of Barbieri's favorite people. If you can't pay up, Sonny and his bone saw are the last things you'll see. 
Working both loan sharking and protection rackets for Barbieri keeps Sonny Blue busy. They offer protection for local liquor stores, but the real money is in the loan sharking side of the house. Loan sharks Red Gallo and Leo Ruggeri dole out high interest loans to people down on their luck, and when they can't pay up they send out the beat down crews. When this doesn't work, Sonny has enforcers Tito Leone and Fede Iocca go to work on the deadbeats. If one of his crew turns on him, Sonny gives them special attention at the slaughterhouse, like former loan shark Ralph McNairy.
In 1968, Blue's racket was taken over by Lincoln Clay, who was working with inside information he received from Bear Donnelly. Lincoln damaged Sonny's protection operation by killing his enforcers, other personnel, and damaging the racket's assets. Once everything fell apart, Blue was drawn out, giving Lincoln the opportunity to confront him. After successfully infiltrating the Roberdeau Meat Packing plant, Lincoln dealt with Sonny Blue and ended his association with the Marcano Crime Family.