One of the reasons why states that don’t border Mexico are becoming so popular with illegal aliens is because those places that were traditional destination points for illegals are for the most part becoming just like Mexico.
The reason the invasion spread from the southwest to all points in America was because there are only so many service jobs and greedy employers in the southwest. They started spreading to all points in search of other lower end jobs, or or labor intensive jobs, and other greedy employers in other states started hiring them by the millions. That's what happened.
In addition to the feds/politicians being paid off and supported by the greedy corporations and business owners that wanted the borders kept wide open. They love illegal low wage labor.
Profits regardless of consequences.