Funny... Any check I can find of the success of the Catholic Church in Latin America shows it to be rather minimal. The historic absence of any denomination hardly means that everyone is Catholic. I think we could all agree that a very strong measure of the Catholicity of any group is the number of priests. But historically, Latin America has been virtually devoid of priests. Instead, what has existed is a very small Catholic community ministering very inadequately to an enormous indigenous community under harsh suppression of anti-clerical regimes which were often funded by Anglosphere leaders who happened to be Protestant (i.e., Roosevelt, Eisenhower, etc.)
Only since John Paul II has a true evangelization of Latin America taken place.
The brutal repression of Catholicism in Latin America is best exemplified by Mexico, a Marxist-Troskyite regime older than the Soviet Union, wherein tens of thousands of Catholic priests and nuns were slaughtered.
2. John Paul the Great lowered the Vatican boom on "liberation" "Theology" after a CELAM Conference in the early 1980s. Several of the leading "Liberation" "Theologians" were defrocked, Dario Castrillon de Hoyos of Columbia who is now a curial cardinal was then sectretary of CELAM and was JP the Great's point man on the ground in Latin America suppressing the liberationist heretics while the then Joseph Cardinal Ratzinger utilized the Holy Office which he chaired to take disciplinary action against the red miscreants. Evangelization of Latin America was active under JP the Great and his efforts began with the suppression of red clergy and nuns. He also visited red Nicaragua and ordered priests in Ortega's regime to resign, which orders were disobeyed, but the message was delivered.
3. The Mexican communists of the Institutional Revolutionary Party (PRI) assassinated Lev Trotsky in Mexico in 1939. The Mexican reds were NOT Trotskyites (although it would have been no more of a feather in their cap if they had been). And, of course, the brutal martyrdom of the Cristeros is yet one more reason for devout Catholics among Mexicans to cross into the US while the crossing is possible.