That's really the rub here. Mexico is incredibly corrupt and mendacious, which is unbecoming of its true status as a client state of the USA. Its entire ruling class, including Sheinbaum (interesting name for a Mexican), is parasitic and enriches themselves off cartel bribes or siphoning funds provided by the United States, like the example in the quote above. As a result, Mexico is teetering on failed state status and in some areas within its borders almost certainly has no governing power.