What is the primary reason why increasing numbers of latin american citizens have immigrated to the united states over the past three decades?

Latin America is comprised of an extremely diverse set of countries, economically, demographically, politically and even culturally. Economic difficulties and political unrest in Venezuela, for example, have created an exodus to the United States. Many of these people are seeking greater economic opportunity and freedom for themselves and their children, as well as an escape from the humanitarian crisis there due to a lack of food medicine and other staples. Other may be fleeing political persecution for speaking out against the government. In another example, many Mexicans have migrated to the US in past decades seeking higher wages and better quality of life. The ongoing cartel drug wars only intensified the migration, as eruptions of violence have driven many away from their home towns.