Initially, Hoffa was very popular. Under Hoffa, the union won substantial gains for its members, bringing all truck drivers under a single collective bargaining agreement, the National Master Freight Agreement, and his achievements won Hoffa both esteem and power. Unfortunately, Hoffa's crimes caught up with him, and he was sentenced to 13 years in 1967 for jury tampering, attempted bribery, and fraud, but just four years later, he was pardoned by President Nixon with one catch: he had to agree to resign as union president and not participate in union activities until 1980.
Unsurprisingly, Hoffa found that he couldn't stay away. He tried to initiate a comeback at the local level with Local 299 in Detroit — where he still had associates and influence — and eventually planned to run again for presidency of the union. Due to Hoffa's eagerness, Bufalino was worried that Hoffa would be willing to trade information to the Justice Department in exchange for lifting the restrictions put on him by Nixon. To keep him quiet, Bufalino ordered the hit on Hoffa, and he purportedly turned to Sheeran to do the job.