With all due respect—there IS an agenda here.
They are not doing this for no reason.
We may be wrong about a direct Agenda, but there certainly is a subtle one.
We are not wrong. The retaking of the Southwest is a dominant theme of Mexican Culture ... and its avowed "foreign policy."
Mexican megalomania knows no bounds. At one point, Mexico was one of the largest countries in the world. At the time of the Mexican War it was certainly larger than the US, had a far greater population, and their armies outnumbered ours by at least a factor of 5, were well-equipped, and led and trained by a European-trained officer corps. We definitely went into that one as the long shot! When we whipped them, the blow to Mexican pride was enormous. They never got over it.
IMHO, they should have stuck with Emperor Maximilian. It was a decent shot at turning into a real country.