A) Close the border (i.e. stop the bleeding).
B) Enforce the laws against hiring illegals. If necessary, make the fines a hundred times higher.
C) Cut off all public services to illegal aliens.
D) Deputize local LE to check immigration status for suspected illegal aliens.
E) Deport via train, plane or bus.
Rinse, repeat...
How would you locate the illegals that you want to deport?