From Pew: 

Catholics remain the largest religious group among Latinos in the United States, even as their share among Latino adults has steadily declined over the past decade, according to a new analysis of Pew Research Center surveys. By contrast, the share of Latinos who identify as Protestants – including evangelical Protestants – has been relatively stable, while the percentage who are religiously unaffiliated has grown substantially over the same period.

As of 2022, 43% of Hispanic adults identify as Catholic, down from 67% in 2010. Even so, Latinos remain about twice as likely as U.S. adults overall to identify as Catholic, and considerably less likely to be Protestant. Meanwhile, the share of Latinos who are religiously unaffiliated (describing themselves as atheist, agnostic or “nothing in particular”) now stands at 30%, up from 10% in 2010 and from 18% a decade ago in 2013. The share of Latinos who are religiously unaffiliated is on par with U.S. adults overall.

The demographic forces shaping the nation’s Latino population also have impacted religious affiliation trends. Young people born in the U.S. – not immigrants – have driven Latino population growth since the 2000s. Among U.S. Latinos ages 18 to 29, 79% were born in the United States.1 About half (49%) of Latinos in this age group now identify as religiously unaffiliated. By contrast, only about one-in-five Latinos ages 50 and older are unaffiliated; most of these older Latinos (56%) were born outside the U.S.2 Overall, 52% of Latino immigrants identify as Catholic and 21% are unaffiliated. U.S.-born Latinos are less likely to be Catholic (36%) and more likely to be unaffiliated (39%), according to a 2022 Pew Research Center survey of Latino adults.

Protestants are the second-largest faith group after Catholics, accounting for 21% of Hispanic adults, a share that has been relatively stable since 2010. During this time, Hispanic Protestants consistently have been more likely to identify as evangelical or born again than to say they are not born again or evangelical.

As of 2022, 15% of Latinos are evangelical Protestants, a share that has remained relatively stable over the past decade. Latino evangelicals have received national attention recently due to the political activism of some evangelical churches. The interest in Latino evangelicals comes as White evangelicals have become a bulwark of support for Republican candidates in U.S. presidential elections, and after elections in which a rising share of Latino voters have supported Republican candidates….

… Another way of measuring religious change is to ask respondents how they were raised, religiously, and see how that compares with their current religious identity.

Most U.S. Latinos (65%) say they were raised Catholic, while far fewer say they were raised Protestant (18%), religiously unaffiliated (13%) or in some other religion (3%). Older Latinos and those who were born outside the U.S. are especially likely to say they were raised Catholic.

But like Americans overall, many Latinos switch away from their childhood religion. As of 2022, one-third of Latino adults indicate that their current religion is different from their childhood religion.

RNS offers this explanation: 

Religion has been referred to as the “largest demographic divider among Hispanic Americans,” according to a 2020 analysis from the Public Religion Research Institute, which found that Latino Protestants are more conservative, Republican and supportive of former President Donald Trump than Latinos who are Catholic or religiously unaffiliated.

With U.S. Latinos regarded as the fastest-growing racial and ethnic group, Republicans, conservative pastors and right-wing organizations have centered faith in their outreach to Latino voters, particularly those who identify as evangelical.

And there’s this: 

Jennifer Hughes, a University of California Riverside associate professor who focuses on the history of Latin American and Latino religions, said that although this is a major shift, it’s important to consider the nuances of Latino Catholic identity.

“Because to say you’re Catholic … if you claim that, it may mean you go to church every Sunday and you go to confession and you’re in good standing,” Hughes said. “Those people who say they’re not Catholic, they could still be culturally Catholic.

“I bet you a lot of those people who are saying, ‘I’m no longer Catholic,’ if you go in their house you may see a little Virgin Mary on their altar.”

To Hughes, anyone who participates in the life of the church, whether it’s in church or through saints and altars in their home, “I would say is Catholic.” Hughes outlined a number of reasons why some Catholics are critical of the church, including the clergy sexual abuse scandal and the rule that women can’t be priests.

“Those things are starting to wear away of support,” she said.