Funny you should mention that,
considering the regions most wracked by the opioid epidemic went overwhelmingly for Trump.
Also, a wall does nothing for the 10 million illegals who are already here, and it does nothing for any illegal who walks 80 miles to the east where the proposed wall is planned to be a fence (Paul Ryan), or any illegal who takes a boat instead.
As long as the federal government isn't cracking down on corporations who hire illegals for cheap labor, it will continue to be a problem. Trump, a huge benefactor of immigrant labor and outsourcing himself, will do nothing where it actually matters.
H1B reform is a currently unfulfilled campaign promise. Where specifically has Trump made progress in this area? Two bipartisan bills have been introduced in Congress on this matter (Lofgren (D), Grassley (R), Durban (D) and were killed or left to flounder by the party hierarchy.
The travel ban does nothing substantive on this matter with regard to the elite, and that's ignoring the fact that it was a poorly-executed gong-show that signifies profound incompetence. There has only been twitter threats of taxing companies who leave, which results in them keeping a token amount of jobs domestically in exchange for ransomed tax breaks and kickbacks, as occurred with Carrier and that car company.