I can assure you “capital” is really happy with the dirt cheap labour that immigration brings. The destruction of the lower class is not their concern.
Part of the reason capital likes anti-immigrant politics is that the end policy result isn't getting rid of unempowered labor, its reducing more people to unempowered labor for capital, rather it is via detention in public facilities that provide labor, directly or indirectly, for private efforts, detention in private facilities that can have work requirements, or "temporary passes" that give the employer control of status. [0]