Policy shifts don't mean reality shifts
Nobody in America is under the illusion that some policy shift by America is going to solve all of Mexico's problems on any timeframe, let alone one of a few years. We have a healthy recognition that problems like the drug trade and the gun trade, the unhealthy interdependence of America's desire for cheap labour...
Follow the the links to the articles cited.
And the NPR piece too.
This analogy is about Afghanistan, but its constrast with Mexico is spot on. I'd like to turn the subject on its head and ask, "What does the US do now in regard to Mexico and Latin America?"