Christie endorsed Trump? I am honestly and without hyperbole shocked.
An incoming Trump administration would suddenly realize that Mexican governments are in general quite helpful to the United States. Consider immigration. Two years ago, the U.S. confronted a wave of migration fleeing the violence in Central America. Then it stopped. Why? Well:
Effectively, Mexico took over border security for the United States. Some details. (The source is biased.) Would that make Mr. Trump think twice about diplomatic hardball?
Conversely, there are some worrying signs that the Central American exodus is overwhelming Mexican efforts:
If there is a another migration wave in the summer, would it help Trump in the general? I think not, to be honest. (I actually have some doubts that there will be all that large a wave.) But it would make an ugly election even uglier.