A dispute between two Philadelphia canvassers for a progressive political group ended in gunfire Monday afternoon. Police said a 46-year-old man was fatally shot while canvassing for the city’s upcoming mayoral primary by a 22-year-old man, who was also out canvassing. Both were working for the organization OnePA. According to the head of the Philadelphia Police Department’s homicide unit, Ernest Ransom, the two men knew each other previously and “had always had a beef.” Ransom said the two crossed paths in East Germantown, where the 46-year-old pulled a gun. The 22-year-old, who has stated that he was acting in self-defense, pulled his own gun out in response and shot the other man in the armpit, authorities said. The older man was pronounced dead just before 4:30 p.m. after being taken to Einstein Medical Center.