Their country doesn't afford them the quality of life they desire; that's a given. The United States does. The logical thing, then, other than being intelligent and applying for citizenship directly, is to petition to join the United States.
They don't have to uproot their entire lives and risk death crossing a border (and deportation thereafter), and they get the increased QoL AND a guaranteed job after their (Mexican) state accedes to the Union. Because there's a HECK of a lot of infrastructure to update. They're part of a first world country now, after all; they need to look it, act it, and live it.
Never mind the increased safety. Drug cartels? Let me introduce you to the US National Guard. They're the steel toed boot to your scorpion.