My friend Jim Chilton sent me a link to his hidden camera videos of smugglers crossing his property. Jim is a rancher with a spread astride the Mexican border, and his property has historically served as a conduit for smugglers entering -- and leaving -- the US. Worth a look if the topic interests you.

The overwhelming share of smuggling across the unsecured border used to be marijuana, and at Jim's ranch, it probably still is. Elsewhere at the border, though, times have changed. Seizures of marijuana by Border Patrol over the unsecured border (that is, not at official crossing points) have declined by 93% since 2012. The reason is simple: We have swapped an enforcement-based regime for a legalize-and-tax system conceptually similar to market-based visas. The legalization of cannabis has made low quality Mexican pot redundant, effectively ending its smuggling into the US. At the same, marijuana legalization has not destroyed America as we know it. A legalize-and-tax regime for marijuana has largely secured the southwest border with relatively minor side effects on the broader US society.

Now, take a look at categories still under enforcement-based regimes. Hard drug seizures are nearly three times the level of 2012. Doesn't look like we're winning the war on drugs, does it? Border Patrol apprehensions of illegal immigrants are even worse, running nearly four times the level of 2012. If we used a legalize-and-tax regime -- market-based visas -- to channel the migrant labor market, the southwest border for illegal entry would look like it does for marijuana, with illegal crossings decreasing by perhaps 90-93%, say, to 40,000 per year from the 1.3 million we project for FY 2021. Therefore, the answer to the question of whether we can use a legalize-and-tax approach to end illegal immigration across the southwest border is 'yes'. Yes, we can. We can end illegal immigation by creating a channel to allow acceptable flows of labor across the border. We don't need walls, legions of Border Patrol agents, or MPP centers. We need a working market-based system.