Maybe it would be better to try some realistic ideas first.
You're going to use illegals to build a fence? Gee... they'd never figure out that's a good way to build the tunnels.
I didn't mention who'd be watching them.
There's an entire system of closed military bases along the border. There's a huge number of combat arms vets like me that would come back in a heartbeat, given some stability of stations and reinstatement of prior rank/pay grade, or farm the entire operation out to KBR as in Iraq and Afghanistan. As it sits right now, I'm going back to Afghanistan to work for them - but would love to pull the duty here on our border.
We'd be the ones catching and watching them. Tunnels my ass.
Let's hear your version of reality, speed.