U.S. reliance on immigrant labour is key to this discussion, and strongly colours all elements. It is a direct legacy of early slave labour (Blacks in the East, native Americans in the West) as well as indentured servitude. Importation of an underprivileged labour class dates to the first days of the Republic as well, and includes the Germans, Irish, Italians, Greeks, Chinese ("coolies"), Mexicans ("Braceros"), and in the post-WWII era an increasing number of Central and Latin American immigrants.
By 1) relying on such labour and 2) denying either lawful entry or any plausible path to permanent status for the vast majority of these workers and their families, not to mention many, many, many broken promises along the way (asylum, DREAM Act, don't get me started on Native American treaties), the U.S. has de facto maintained a legally-underprivileged and disadvantaged working class long after the statutory prohibition of (most) slavery and indentured servitude.
Yes, there are also economic and political circumstances within the US geopolitical orbit which encourage inward migration. That too cannot be separated from long-standing U.S. foreign, economic, and military policies within the region.
Two of the most notable recent status enhancement laws in the US have been DREAM (previously mentioned) and DACA (deferred action for childhood arrivals). Both were passed under and with the strong support of Democratic administrations.
Both have seen repeated attempts at repeal by the GOP and present US Administration, and effective status rescinded.
The GOP has embraced the historical Democratic position with enthusiasm. The Democratic party has stood for civil rights since the 1960s, with former segregationists and white nationalists first joining, then taking over, the GOP. See: <https://news.ycombinator.com/item?id=49402261>.
Attempting to resurrect long-dead, long-irrelevant, and now fully-reversed political descriptions can be taken as a prima facie declaration of bad faith.
Not so fast. The victimhood/systemic-inequality mentality has a perhaps counterintuitive effect: while on the surface it does seem to help individuals, collectively it perpetuates an underclass.
25 years ago, no one thought twice if a minority member or person of color was in a prestigious position. Now, many people silently wonder if the desire to manipulate the distribution of various previously-protected categories contributed to the decision to hire that person.
"Among black students in colleges and universities, those admitted under lower standards face a higher failure rate and those admitted under the same standards as other students graduate with their credentials under a cloud of suspicion because of double standards for minority students in general." -- Thomas Sowell
By 1) relying on such labour and 2) denying either lawful entry or any plausible path to permanent status for the vast majority of these workers and their families, not to mention many, many, many broken promises along the way (asylum, DREAM Act, don't get me started on Native American treaties), the U.S. has de facto maintained a legally-underprivileged and disadvantaged working class long after the statutory prohibition of (most) slavery and indentured servitude.
Yes, there are also economic and political circumstances within the US geopolitical orbit which encourage inward migration. That too cannot be separated from long-standing U.S. foreign, economic, and military policies within the region.