In the 1960s, California lettuce growers needed workers for their fields. To hire Americans, the managers had to pay the government mandated minimum wage, which they opposed. Many Republicans opposed it also, though it was the law. Lettuce growers decided to import Mexican workers, who could not be subject to the minimum wage. To be certain, many of these Mexicans were desperate for work and income. However, traveling back and forth across the border was difficult, inconvenient and expensive. So many of them found the means to stay in the United States, though they were illegal aliens. Union leader Cesar Chavez argued that many of the laborers were being abused by the lettuce managers. Regardless, it was the start of massive illegal migration into the US. Companies were not penalized, and workers were paid low wages. Many migrant workers eventually infiltrated throughout the country, including the large cities. Even Amish communities hired them. Along with the migrant workers came the drug dealers and undesirable elements. Not all were Mexican, many came from Central and South America.
Now we are saddled with the problem. Will the wall resolve the problem? I doubt it. Immigrants and drug dealers have been circumventing the borders for years by scaling, tunneling and flying over them.
Yes, we need to determine who is entering our country and filtrate the undesirables. But America is still a haven for the oppressed and the home of opportunity. Probably most of us would not be here otherwise. So now we need to fairly and reasonably resolve the problem.