Mexico’s overwhelming interdependency with the US as well as the chronic weakness of the central government makes it improbable for any government in Mexico to survive even for a few month any serious US suspicion that it is moving towards the role of being significant liability to the US in the competition with China.
The exact same a[plies to Brazil, to a lesser degree. A government on course to make Brazil a liability for the US might survive as long as one or two election cycle in Brazil. But the degree is still overwhelmingly large in grand scheme of things and it will go no farther.
The problem fir China in its competition with the US is the US had nearly 200 years in which to acquire levers to prevent Latin America from becoming a liability to the US. Even before the US became a preeminent global power, other global powers were preoccupied with other concerns, and not one mounted any serious, sustained challenges to american efforts to gain hegemony over Central America and prevent European inroad into South America. The only challenges to the US hegemony inside Latin America really had been ideological, as an reaction by the disadvantaged classes in the society against the consequence of American sponsored exploitation, or ethnic, as in German emigrants supporting a pro-german and thus anti-american line during the two worlds, and not geopolitical or economic, as in securing a competitive position for a country against the US in the international arena.
