The extremely uneducated and superstitious underclasses of Mexico and Latin America do not need to be co-opted by communists after they come to the US. Marxism is being promulgated as the answer to all problems in those countries and has been for a few decades now. There is no need to propagandize those people into communism they are raised on it.
The problem is Marxism has failed to bring the people of Cuba or anyplace else out of poverty. China only started to prosper when it junked Maoist economics.
However, hundreds of millions of Chinese still live in poverty with few resources.
Marxism replaces "slavery" to corporations with slavery to the state. Everyone is equal there: equally miserable.
Unfortunately, it is not only the underclass, but the same phenomenon is noticed in the upper middle class as well. My son's in-laws, for instance. I have come to think almost nobody in Mexico is aware of anything comparable to us.