A lot of Baptists were killed during colonial and post colonial days, but most of them were driven out - it was the NE Catholics and the Quakers that took the brunt of Republican Reformist anger. The Baptists went South and established plantations (along with the firm establishment of the slave trade in the US). Where were the Irish to go?
It wasn't the Irish who rejected the Republican Party. It was the Republican Party who rejected the immigrant Catholics of the late 1800s. It takes generations to erase that sort of rejection. For example, look at the Serbs and the Croats - brothers, really, but bitter enemies.
So I'm sorry sir, but that particular sort of short-hand historical portrayal which you seem to be bringing here as accurate, is too much over-simplification and blend of misidentification (leaving Republicans holding the bag) that is part & parcel of the impossibly screwed-up worldview of today's American liberals, which they both promote and further distort.