The change would be them better controlling the flow of fentanyl and migrants over the border. From the illegal migration front, objectively Trump has done an amazing job stopping the flow. While more difficult to assess, it would be right to assume the flow of fentanyl has also been greatly stemmed with this new administration. Now, you could argue that if he’s doing such a good job why does he need the tariffs, you could also argue that the tariffs, or threat there of, brought about certain changes from the Mexican government which also aided in the changes.