A simple solution for this illegal alien problem is for the country of Mexico to (become annexed) to the United States. Although this sounds preposterous, think about it.
Let the Mexican people vote on this. It seems as though they all want to be here, and not in Mexico.
The United States population is about 300 million. The population of Mexico is about 100 million. The GDP of the US is $13 trillion. The GDP of Mexico is more than $1 trillion.
In 10 plus years, the privatization of the vast mineral, oil and natural resources (beaches, oceans, mountains) would flood this country with wealth that would be absolutely staggering.
Allow the sale of all property legally, ocean front included, which would create the necessary jobs to sustain a decent living for the masses.
The U.S. could contribute hundreds of billions of dollars to this plan, and still be many billions of dollars ahead. But, alas, something this simple would never work, because the politicians on both sides of the border would need heavier lined pockets.
It has been thought over the years, that the Mexican government has been slightly more corrupt than the U.S. government, but only the experts could be certain.
Although it does sound a little extreme, I think if both sides looked at this plan objectively, they might find this plan to be very workable, and advantageous for both countries.