An extremely unwise bet. When the Mexican upper class comes to the US, whether it is to shop at the finest shops, or get an Ivy League MBA, they are 100% documented, and well funded. Any relative of his in this country will fly here first class and stay at hotels highly regarded restaurants, they don't sneak under across the border and sleep under bridges.
The Mexican upper class is upset for two reasons, and neither has anything to do with their members losing jobs as maids or brick layers. The first is that "kick the Gringo" plays well in domestic Mexican politics.
The second is that illegal immigration is the safety valve that keeps pressure for reform from building up, and threatening the Mexican upper class. Millions of peasants and lower middle class Mexicans come to this country because the worst jobs and housing we have is far, far, better than anything they can get in Mexico.
Put all, or even 1/2, of those people back in Mexico, and they will want jobs, housing and opportunity like they had in the US. Mexico cannot provide that sort of opportunity, unless it reforms its economy and government to allow Mexicans the opportunity to open businesses and succeed based on how good a business person they are, as opposed to success being predicated on being plugged into the corrupt, cronyism driven system they have now.
Mexico would benefit from reform, but the Mexican upper class might not. If the business that makes you rich succeeds because you are protected by the government from competition, you are threatened by freedom and free competition. You might agree to reform, if the alternative is revolution brought on the extreme poverty caused by your small, corrupt economy. The Mexican upper class has not had to face that dilemma, because it could export enough of its surplus population to the US. If that ends, they are looking at reform or revolution.