In the late 1800s California nativism was the cause for most of the discrimination. An anti-miscegenation law was passed in 1850 which banned unions between "negroes", "mulattoes" and "Mongolians". To combat bad immigration, the Commission in Lunacy (1896) (renamed Department of Institutions in 1920) created the Office of Deportation Agent in 1915. This Office took in upon itself to deport any non-Americans who displayed feeble-mindedness.
Eugenics was powered by race superiority. Deportations where the first part of many programs to reduce "feeble-mindedness"