The rapid growth of the Hispanic population in New Mexico was mainly due to two factors, one being the migration of more Hispanic people into the area,a and the other being the high birthrates of this population.
New Mexico already had Hispanic population in this period, but its proximity to Mexico and the unrest in Mexico led to more people moving on the other side of the border and into New Mexico. That led to rapid increase of the Hispanic population in this state. Also, this population was mostly involved in agriculture, and lot of work force was needed, so that meant lot of children per family, which significantly increased the Hispanic population in very short period of time.