The esteemed Irish ecclesiastical historian Donal Kerr assessed McNally as an "O'Connellite Bishop and Reforming Pastor", the son of a 'middling farmer' who grew up in the aftermath of the 1798 Rising and would live long enough to see the stirrings of the Fenian Rising. He was O'Connellite in that he tolerated his clergy speaking on political matters, specifically the issue of the day which was the Repeal of the 1800/1 Acts of Union 1800 and in this regard he was in conflict with his Metropolitan bishop William Crolly.