Even if a large quantity of the workers are foreign, they do spend truckloads of their fat paychecks in the US. Or what you are saying is that trickle-down economy doesn't apply to foreigners, then?
[1]: http://www.nytimes.com/2013/04/28/us/politics/immigrants-fin...
[2]: https://www.nytimes.com/interactive/2017/04/26/us/politics/w...