Let’s say future President Trump pushes to make marijuana a state issue and get the feds out of it. Under this scenario, the federal government would remove any federal laws against marijuana and tax it like liquor and cigarettes.

Now let’s say those tax dollars are dedicated to the cost of constructing a border wall with Mexico.

And let’s say the loosening of marijuana laws in the United States dries up much of the illegal weed business coming from Mexico. You don’t need to import what you can grow locally and legally.

Under this scenario, Mexico would pay for the wall by losing billions in illegal weed money to U.S. growers who are then taxed on income.

I don’t think this is what Trump has in mind, but I have a hard time seeing why it wouldn’t work.