I think the most reasonable thing to do is to make a limited military incursion into Mexico.
Then close it off, in the meantime tell the congress to pass a law to solve the problem.
Somehow I think the dems will be in a huge hurry to actually do something. maybe not.
I think the most reasonable thing to do is to make Mexico stop this invasion. We should just take over their corrupt country, install a federal republic, and leave.
There is no need to invade Mexico. Just deport the invaders. Simple as that!