I think the importance these days is even more critical when one considers the enormous number of illegal aliens who hail from these areas.
The legal immigrants usually hail from the upper middle class and lower upper classes. The illegals are from the lower classes who have been subjected to radical communist propaganda and agitation. This is also true of middle class university graduates as well. Think our universities are a haven for communists? Look at the major departments in most Latin American Universities and they make American radical professors look tame by comparison.
There is also a racial element in all of this. Indigenous peoples are the fastest growing segment in most South American countries and there is a deep and festering resentment of europeans (caucasians) which are exploited by the radical left to promote their agenda. The United States is seen as the biggest European oppressor.
In my conversations with illegal mexicans and central americans ( who happen to be cholos or mestizos) that have invaded my neighborhood, this resentment is apparent and they don't even hide from other hispanics. Naturally when I speak spanish they assume I already know it anyway. They have a deep seated hatred for all things white which they brought along from their own cultures.
Most Americans are un-fazed by all of this, since it is a subculture that surrounds them but which they are unaware of. Groups such as Aztlan on the other hand have been very deft at exploiting it.
We had better wake up to this because demographics will make these hispanics the largest ethnic group by the end of the century. This has enormous implications in both politics and economics and rest assured that racial arsonists and pimps will exploit it to the hilt unless we get a handle on it now rather than later.