From Pew:
Catholicism’s roots in the United States run deep. Nearly half of U.S. adults (47%) claim some connection to the Catholic faith. A new Pew Research Center survey finds that:
- 20% of U.S. adults are Catholics: They say they are Catholic when asked about their present religion.
- 9% of U.S adults are “cultural Catholics”: They don’t identify with Catholicism religiously, but they say “yes” when asked whether “aside from religion” they consider themselves Catholic in any way (for example, ethnically, culturally, or because of their family background).
- 9% are former Catholics: They neither identify as Catholic religiously nor consider themselves culturally Catholic, but they say they were raised in the Catholic faith.
- 9% are connected to Catholicism in other ways: They are not Catholic, culturally Catholic or formerly Catholic, but they have a Catholic parent, spouse or partner or they say “yes” when asked if they ever attend Catholic Mass.1