Mexico receives billions in remittances each year.
Saying "ohoho but $5 isn't that much, checkmate!" is only focusing on a single drop of the flood of money out of the us economy. If money isn't being spent here, we suffer, period.
If you want to focus on the fact that $5 is small, you can do that, but when the yearly remittances are around 27 BILLION dollars, that's 5,400,000,000 droplets of $5.