Scots-Irish (Orange) is just another way of saying "not Catholic". The discrimination faced by the "Green Irish" had nothing to do with Ireland and everything to do with Religion.
BTW. My mother (the daughter of a Green Irish immigrant) married my father (the son of an Orange Irish immigrant). Naturally, I fight with myself a lot --- and enjoy it. ;~))
Same deal here.........mother was Irish Catholic.......father was Scots-Irish Presbyterian. As with most Catholics.........my mother is a diehard liberal/socialist while my father was a staunch Southern Conservative.