The Teamsters president’s decision to speak at the Republican National Convention where Donald Trump is expected to win his party’s nomination has outraged a large swath of members within the powerful union, the New York Times reports. President Sean O’Brien’s argument that his appearance in Milwaukee represents a “savvy” political maneuver reportedly has International Brotherhood of Teamsters leadership muttering union members’ most deplored four-letter word: “Scab.” Teamster Vice President John Palmer went so far as to publish a scathing editorial Wednesday condemning O’Brien as a disgrace a…