>About 15 years ago in my hometown, not far from Tijuana, there was a
>noteable increase in the number of would-be immigrants seeking and
>finding employment at residences, gardening and other domestic work.
The "illegal" employment situation is cloudy in California, largely because the State unofficialy tolerates (while Officially Intolerant) the flow of migrant workers -- competitive prices in the agribusiness world depend on cheap, plentiful, disorganized labor. The fact that this spills over into other areas (like you say, domestic work) is probably aberrant.
/jordan