Not all Irish people. Just the ones who's utter disdain for the mainland seems to be forgotten when it comes to supporting a football team. If these people can't stand England so much because of history, why in the name of good fuck, would they want to be associated with an English football team? Smacks of rank hypocrisy to me.
As for the Irishmen who support Rangers or Celtic, if anyone tells me its not down to historical sectarian divides then frankly I think they need their heads testing. To back this up, how many protestant Irishman support Celtic or vice versa?