If you look at the map in the middle of this article you can click through and see how the states rank in emergency room care. The one thing you'll notice is that the lowest emergency room quality can be found in the southern coastal regions.
While the article doesn't come out and say anything about the country of origins of the people using the emergency room as their personal doctors, it does have a section entitled, "Too many patients; too few resources." Within that section it says, "The organization said rising costs were forcing hospitals to close emergency departments at the same time that demand for their services was skyrocketing, thanks to a rise in the number of Americans who seek treatment in the emergency room because they have no health insurance."
So who are these people who don't have health insurance? For the most part illegal aliens. You can use a map that MSNBC put together showing where the uninsured are. Now overlay this map of the concentration of the concentrations of illegal aliens are and you see a disturbing trend.
Illegal aliens who don't have insurance or pay taxes don't pay for emergency room visits. They tend to wait until they're on death's door before going to an emergency room which drives up the costs even more.