Irish unionists use the two nations theory as a basis for opposing a movement that agitated for self-government that was the dominant political movement of Irish nationalism until when? 
Two nations theory (Ireland): In Ireland, the two nations theory holds that Ulster Protestants form a distinct Irish nation. Irish Home Rule movement: The Irish Home Rule movement was a movement that agitated for self-government for Ireland within the United Kingdom of Great Britain and Ireland. Irish Home Rule movement:  It was the dominant political movement of Irish nationalism from 1870 to the end of World War I.
i don't know