Mexico dominates USA instead, goals of reverse Manifest Destiny?

Let's say that it plays out as it is stated in the titles. Mexico retains all her territories, including Texas, losses from 1848, whole deal. What would be the goals of such Mexico?

I presume they would be inclined to try an conquer every single ounce of land that belonged to Spain in the N.America (only Florida comes to mind ) and maybe denying US Pacific coastal access by taking Oregon and Washington states.

Imagining Mexican Illinois or Ohio would be stupid:p. Any more ideas?
 
If you prevent the Constitution from being signed and a federal state from being created, Mexico will have the run of the North American continent.
 
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