General Discussion

Roman Catholic is not the only "Christian" Catholic in the US, there are some Opus Dei/Rad Trad types who believe that since Vatican II, Rome was no longer Catholic enough for them, and they only nominally listen the Pope.
Especially a lot of the pro - Fascist US Bishops who are butt-hurt over being called out for property/financial shady dealings and of course, the child abuse they had been indulging in since the mid-19th century. There's enough political tension around the US bishops and Pope Leo that some former (disgraced) bishops have been talking about a split, as there is with the various Eastern Orthodox churches.
So, as was explained to me by various Catholic devout over the years, using the term Christian Catholic does not necessarily mean Catholic following the Pope in Rome.
It could also mean member of a Latin Mass strip mall "Catholic" church run by a former deacon or Dominican seminary student who went Rad Trad.