In the 1930s, the US was notorious for having a very complex and strict immigration system that tried to keep out as many people as possible so as to "reduce" the "burden" immigrants would place on the US. In particular, right up into World War II this would be used to try to keep out as many Jews as possible from the US (most notoriously the "voyage of the damned", of which my parents used to be friends with a survivor of that voyage). South of the Río Grande, however, Mexico was different - under its President, Lázaro Cárdenas del Río, anyone who was persecuted by fascist régimes around the world were welcome, especially Jews and refugees from the Spanish Civil War. Which leads to this question - could it have been possible for the US to try to shift more of its ever-increasing "backlog" in the 1930s and 1940s towards Mexican embassies and consulates to the effect that it would be "easier/quicker" to do so? And then, if one so wanted to go to the US rather than stay in Mexico and take advantage of Cárdenas' and the Mexican people's generosity, would be better able to try to negotiate passage to the US from Mexico?