The WSJ has a useful rundown of how a group of Mexican businessmen, politicians and activists are working to make it harder for Trump to deport Mexican nationals.

• An ad campaign urging people to fight their deportations in court. The goal is to gum up the court system so badly it can't push through deportation and extradition orders.
• $50 million from the government to help illegal immigrants facing deportation.
• "President Enrique Peña Nieto has instructed the country's 50 consulates in the U.S. to defend migrants."
• Politicians threatening to stop cooperating with the U.S. on anti-drug and counter-terror operations.
• A group of lawmakers are working on legislation to ban Mexico paying for Trump's wall.