Unless the goal was to never stop them to begin with, so you attempt to discredit any attempts at doing so.
If I were King, that wall would start being built on the 22nd of January my 1st year. It would be of concrete, buried 10' deep and 40' tall with triple razor wire at the base and razor wire at the top. Followed 20' inside by a 30' tall wire fence(posts embedded in the 10' deep footer) There would be seismic monitors between the two barriers. Explosives would be used to collapse any tunnels and the holes refilled. There would be guard towers and those towers would be manned by armed guards with shoot on sight orders for any possible "Terrorist" coming out of the ground( should anyone ever be able to do so)
This would run the entire southern border to halt child sex smugglers and drug mules.
To stop the Undocumented Democrat Voters,, I would sign an executive order changing the EXISTING penalty (that is rarely if ever enforced) for employing ANYONE without a MATCHING SSN# and photo-ID from a slap on the wrist to $1,000,000 fine and 5 years at hard labor( helping build the wall or other "Public work" projects)
Since 95% of the Undocumented Democrat Voters come here for the money and couldn't get any non gang related work, they would self deport and go home or to Canada and "F" up that country. As for their kids, they would take them with them or sign over guardianship to someone who will assume all responsibility INCLUDING medical, shelter, food etc. The US Taxpayer would NOT pay to raise the offspring of Criminal Invaders ( until we can amend the Constitution and remove anchor baby automatic citizenship)
As for funding the wall, every non commercial money transaction would have a 25% Federal Excise tax and every Federal Drug Possession case would have all assets seized go to the "Security of America" fund and the money used for the wall and more agents, drones, etc to patrol the Canadian border.
To aid with this funding, I would have Congress ( no Senate Filibuster be allowed) to institute an annual $2,000 per year License renewal fee for all Lawyers/$10,000 for all Law Firms to practice law in any Federal Court. They make millions a year off Class Action Suits so that fee could be adjusted upward if evidence suggests it is needed.
I would also add a $100.00 a Barrel tax on ALL oil/gasoline imported from terrorist sponsoring countries. That would be ALL Moslem nations plus Venezuela.
Be a boon for US companies fracking in America.
There WOULD be openings to allow for International Vehicular travel. Infrared sensors would be installed to check all vehicles for hidden human/animal cargo as they que up to pass through border crossings.
As for airborne drug smugglers, infra-red seeing drones and Doppler radar all along BOTH borders would monitor all low flying aircraft ( especially those flying without running lights) or those who have not logged in a flight plan with the US FAA. Apache helicopters / or F-16s ( relocated from some of the 140 FOREIGN Nations we are guarding that need to guard their own damned countries) would be dispatched to signal the aircraft to land at the nearest airport. If they refuse, they become so much litter that has to be picked up by White Collar criminals in orange jump suits doing their part to "Make America Great Again"..