The Mexican government KNOWS that an American President can make them pay for just about anything. There are so many ways to cut finances, aid, loans, World Bank, favored trading partner status.
They also can see the polls, and probably have their own political experts who are showing that Trump might just win.
So they are cutting their bets, making nice, and trying to save the next four years.
I don’t see how the Secret Service could possibly keep Donald Trump safe in the land of “Plata O’ Plomo,” and I certainly question the motive of any of his advisers who advised him to take this trip.