Immigrants are clustered in entirely immigrant-dominated sectors of the labor market for the most part, so there's very little direct competition, but US-born non-college educated workers are the main group that has suffered under the degradation of once good jobs. Some of those jobs have completely vanished, and others have been transformed in ways that make them unacceptable to most US-born workers. What I'm suggesting is the scapegoating of immigrants is a convenience explanation for a complicated set of economic trends that have reversed the fortunes of many, especially white, non-college educated men who once had good union jobs, that are gone.