I predict how Trump will pay for the 'wall' and 'deportation force'

Property Forfeiture.

Been here 20 years Illegally? You're going home and may take you 5 years to get back.

Have a house you're been paying taxes on? Forfeit to be sold to pay for your crimes.
Vehicle? Forfeit.
Bank account? Forfeit.
Personal goods. Forfeit, you get sent back with what you can carry.

.... and his Brown Shirts in waiting will cheer and fight for the right to buy the stuff.