He's making a simple problem very complex - most likely on purpose. Just build the wall and then the other ideas can be discussed.
With all due respect, I don't think it's that simple. He did mention building a wall in urban areas, but the rural areas are massive. How much it would cost (and the time involved) to construct a physical fence, I have no idea. It seems to me we can implement the best technology in the world much more quickly.
I also think he had to address all aspects of the issue tonight--I heard this a.m. on the radio that he's got the worst poll numbers of any president ever recorded, IIRC.