In which I originate from, and I realize that the indicating is the same in Mexico, "chusma" is used to refer to "low course" persons. The best English equal I'm able to visualize is "riff-raff" Nos cuentas el origen de la expresión “dormir a pierna suelta” a quienes lo desconocíamos: https://residential-electrician-b38261.ampblogs.com/getting-my-contactos-chusma-to-work-70175140