There are plenty of black market money senders ready to step up if uncle sugar makes it too hard to sent money the legit way.
It's all part of a giant filter.
Fuck them when they send their money back.
Cut off all benefits or healthcare.
Install exponentially growing fines and eventual personal corporate liability (just like Sarbanes-Oxley) for employers found to be employing illegals
Expand the identification and cataloging via biometrics with a new policy that says you and your immediate family are ineligable for ever applying for immigration into the US if we catch you a second time after youve been scanned and cataloged
Second time offenders are then detained in work camps on the border
Everything you need to do this, we already have. Its a simple matter of doing it. Give me the keys and I'd have it done within months.
We don't even need the wall. We just need to bring the pain.