Seeing how a batch of executive orders issued by President Donald Trump on the first day of his presidency effectively closed down the Mexican border for migrants headed to the United States, Ronald Alvarez had the sinking feeling that he and his family had just lost the race for salvation.

There is no census, and migrants come and go, but the majority of people in La Soledad appear to be from Venezuela, the once-wealthy South American nation that has seen an exodus of more than 7 million amid an economic, social and political crackup.