Excellant post. The key point being the 8 month political cycle. I am not sure why (actually I d know why), but people seem to think all problems can be solved in a 60 minute drama show.
To add to what you say, if Mexico continues to slide back, it will look for "financial" support from somewhere else. That somewhere else may include some folks that we really don't want knocking on our doors economically, where they can even easier dump cheap goods (like China or Russia). I could even see Japan jumping on that and getting into the 21st century version of a World war with us, but doing so on a large economic scale.
In addition a lot of the foreign investment that we see would dry up for the closer and cheaper confines just south of the border. Less taxes, NAFTA in place, makes it quite attractive.