Maybe this helps explain the RC bishops’ support for open immigration, contrary to the views of those in the pews:

Among U.S. adults, about the same percentage — 24 — call themselves Catholic as in the past, but that statistic masks significant turnover. The percentage has held up primarily because of the huge number of recent Latino immigrants, who are largely Catholic, the survey found. Sixty-eight percent of people raised Catholic still identify with their childhood denomination, compared with 80 percent of Protestants and 76 percent of Jews.