Racism aside (because racism is retarded) foreign labor does drive down rates in all industries. It is for cultural reasons, not because foreigners are some kind of bad people. The thing is in many cultures they live with many people in the household, many may have 3 generations in a house, living with parents is normal and not frowned on. So you will have TONS of people contributing to the bills in a household. If you had five or six people pitching in for bills in a house, $20 an hour is damn good money, you are doing quite well at that rate.

Americans in particular value independence. They want to move out and get their own place, living with your parents for an extended time into adulthood is definitely chastised. Well living independently is much more expensive. Americans typically therefore have alot less people contributing to bills in the household.

This isn't to even mention things like childcare. In many foreign cultures they will never need a babysitter. Lots of adults in a household means plenty of people to babysit and such, a HUGE cost savings. For some cultures multiple people sharing a room is like no big deal, for Americans we can't imagine that.

That is just kinda scratching the surface, but you get the point. Americans cannot compete with many foreigners in terms of the wages they can work for. Due to massive differences in culture and lifestyle, the necessary money each needs to make in order to make ends meet is vastly different. If you are part of a giant household with many people paying bills, free babysitting and such, you need alot less money than a household with only 1 or 2 people paying bills, who have children that you must pay for daycare for and such.

This is like the most overlooked aspect ever, and the big thing people don't understand. Culture and lifestyle drastically affects the wages certain people need in order to survive.