When construction of the wall starts, announce that all persons residing illegally in the US have one or maybe two years to leave or face arrest and prosecution. At the same time enforce all existing immigration laws, including E-verify, and prosecute anyone hiring illegals, and cut off all public assistance to illegals, and defund Sanctuary Cities. Shut off money transfers from the US to Mexico. At the same time start vigorously deporting all criminal aliens. I think that would rid the country of several million illegals, but probably not all of them. The rest could be dealt with as they turn-up.
Just checked Trump’s own positions from his website:
~Triple the number of ICE officers
~Nationwide e-verify. This simple measure will protect jobs for unemployed Americans.
~Mandatory return of all criminal aliens.
~Detention—not catch-and-release. Illegal aliens apprehended crossing the border must be detained until they are sent home, no more catch-and-release.
~Defund sanctuary cities.
~Enhanced penalties for overstaying a visa.
~Cooperate with local gang task forces. ICE officers should accompany local police departments conducting raids of violent street gangs like MS-13 and the 18th street gang, which have terrorized the country. All illegal aliens in gangs should be apprehended and deported.
~End birthright citizenship.
These things are explained in greater detail on his website:
https://www.donaldjtrump.com/positions/immigration-reform
All that and deported when they come in contact with law enforcement, etc.
the problem would be completely taken care of. No mass deportations needed.