in N.I the Catholics are not even Catholic anymore. You can see this with Sinn Fein championing abortion & globalism. As for the Protestants ? i would guess that football affiliation is stronger than faith.
Back in 1921, if you hopped back and forth over the N.I border, you would witness two different cultures of two different nations. Today much of Dublin is the same as Thornton Heath. So really the border is looking slightly ridiculous. The chinese takeaway in Newry is different to the one in Dundalk ....only regarding what money they take. And the staff, working there, dont care what flag you wave at them.