Again, no matter how much someone has in the way of "guts," NO PRESIDENT can seriously change another country's policies unless you propose an invasion of Mexico.
I have a much better solution: build a wall, rabidly pursue all employers who hire illegals, and immediately deport anyone who is illegally here.
It really is simple, and has nothing to do with the Me-hee-co economy.
That is apparent.
Our government is "gutless," but not becuase they won't enforce the border laws. Silly.
Thinking past the obvious Jr high short term forced based "solution" to a policy which is the only one which will actually address the problem is a little more difficult.
The President is only one of the people who can "seriously change" another countries' policy.
Do we give "aid" to Mexico? Do we agree to beneficial trade policies with them? Do they benefit from any other agreements with us?
Of course. And the list is long.
Pressure needs to be brought to bear on them.
Of course that's not as much fun as pointing guns at a bunch of people, foreign and domestic.