Among the facts posted recently by Pew:
There are roughly 51 million Catholic adults in the U.S., accounting for about one-fifth of the total U.S. adult population, according to Pew Research Center’s 2014 Religious Landscape Study. That study found that the share of Americans who are Catholic declined from 24% in 2007 to 21% in 2014.
Catholicism has experienced a greater net loss due to religious switching than has any other religious tradition in the U.S. Overall, 13% of all U.S. adults are former Catholics – people who say they were raised in the faith, but now identify as religious “nones,” as Protestants, or with another religion. By contrast, 2% of U.S. adults are converts to Catholicism – people who now identify as Catholic after having been raised in another religion (or no religion). This means that there are 6.5 former Catholics in the U.S. for every convert to the faith. No other religious group analyzed in the 2014 Religious Landscape Study has experienced anything close to this ratio of losses to gains via religious switching.Politically, Catholic registered voters are evenly split between those who identify with or lean toward the Democratic Party (47%) and those who favor the GOP (46%). In their partisanship, U.S. Catholics are deeply divided along racial and ethnic lines. Most Hispanic Catholics identify with or lean toward the Democratic Party, while 54% of white Catholics today identify with or lean toward the GOP.
Large majorities of U.S. Catholics have admired Pope Francis throughout his tenure, but there are signs of growing discontent. The latest Pew Research Center polling, conducted in January 2018 (long before the latest revelations about sex scandals in the U.S. Catholic Church), found that the share of U.S. Catholics who gave Francis “excellent” or “good” marks for his handling of the sex abuse scandal in the church was 10 points lower in 2018 than it had been in 2015 (45% vs. 55%). The January 2018 survey also found that disenchantment with Pope Francis was especially pronounced among Catholics on the political right (i.e., among those who identify with or lean toward the Republican Party).