Mexico, by any measure, is among the most corrupt nations.The poor are as much to blame for this as the rich, though: given the chance, the average Mexican would gladly trade places with the corrupt officials.
I can't argue with you on that. Corruption occurs everywhere but when a culture of corruption takes hold, it has bad effects from one degree or another when every it reaches a certain critical point. See Detroit or New Orleans. In Mexico, it has held sway for over 100 years and is totally ingrained from the top to the bottom of society. There is no level to which one can look to for help.
There is no reason, other than corruption, for that nation to have so many poor. It's all so unnecessary.