This is the Cato Daily Podcast for Wednesday, January 31st, 2018.

I'm Caleb Brown.

The technology of surveilling the U.S. water has never been better, but it's not

clear what security benefits it provides, while the costs to liberty of some of that technology

is particularly troubling. Cato's David Beer and Matthew Feeney discussed the new tech of border surveillance.

Where did this discussion begin with securing the border?

How far does that idea go back in at least recent political history?

Well, you're really talking about the origins of illegal immigration

in the United States.

And so you really have to talk about the changes

that were made in the 1960s that eliminated

really the largest guest worker program in the history of the United States, the

bracero guest worker program that was allowing Mexican farm laborers to

enter the United States legally every year, about a half a million or so at its height,

we're entering the United States with legal work permits.

When that was eliminated, a circular flow of illegal immigration replaced it,

where people would come across the border from Mexico for a few months,

work in Arizona, California, and Texas, and then they would go home at the end of the season.

And this was hugely beneficial to agriculture in those regions and so Congress started debating really in the

70s but then it really heated up in the 1980s when you had more than a million Mexicans crossing the border

illegally every year and during the 1980s you had a debate about how do you

address first of all the people who've been here for a long time

...