The United States has no official mandated religion due to the first amendment, which in effect declares freedom from religion. In practice has been Protestant in the decision that were made for nearly all of our history. To date we have only elected two Catholic presidents.
"Amendment I
Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the government for a redress of grievances.
"
Please take a lot at the list of all 116 US Supreme Court Justices attached. There were 5 Catholic justices appointed between 1789 and 1956, that is 167 years . Things started trending away from the historical appointment of Protestants with Ronald Reagan who appointed to Catholic Justices Antonin and Kennedy. George H. Bush appointed Justice Thomas in 1991, then George W. Bush appointed two, Justices Roberts and Alito, Obama appointed Sotomayor and Trump appointed Kavanaugh. It appears that the shift in the last 32 years may indicate some particular agenda which has not been openly discussed.
By the way we have had only two Catholic presidents, Kennedy and Biden.