As the race for the Republican presidential nomination continues, the right’s anti-immigration rhetoric is growing louder and more ferocious. It’s hard not to wonder, is there some kind of ceiling? Will we soon reach the limit on conservative extremism?

I can’t answer that with confidence, but I certainly hope that pro-slavery arguments represent the right-wing cliff.

[J]ust this week, Media Matters reported that well-known conservative radio host Jan Mickelson said that any undocumented immigrant that does not self-deport by a certain time-frame should become “an asset of the state.” “Well, I think everybody would believe it sounds like slavery?” said one listener who called in to challenge Mickelson. “Well, what’s wrong with slavery?” he responded.

This is, alas, quite real. Earlier this week, Mickelson, an influential conservative in Iowa, told his radio audience that he has a bold, new plan to deal with undocumented immigrants. Under the host’s vision, those who don’t deport themselves voluntarily after 60 days’ notice would automatically become “property of the state” and forced into “compelled labor.”

That labor would include – you guessed it – building a wall along the U.S./Mexican border.

“We will compel your labor,” Mickelson said. “You would belong to these United States. You show up without an invitation, you get to be an asset. You get to be a construction worker.”

When a listener raised the question of slavery, the radio host not only asked “Well, what’s wrong with slavery?” he soon after added, “You think I’m just pulling your leg. I am not.”

Yesterday, Mickelson talked to Media Matters and described his plan as “constitutionally defensible, legally defensible, morally defensible, biblically defensible and historically defensible.”

Despite the fact that Mickelson said on the air that he wasn’t kidding, when Media Matters asked if he expected GOP candidates to agree with his plan, the host replied, “[M]ost of them would understand my point isn’t serious, the point is philosophical.”

I’m not altogether sure what that means. Mickelson supports the philosophy of enslaving undocumented immigrants?

To be sure, there are all kinds of radio hosts who make all kinds of radical comments every day. Most are worth ignoring. But let’s not overlook this key detail from the Media Matters report:

Mickelson has a history of making racially -charged, anti-immigrant remarks but he also has a strong pull with conservative caucus voters in Iowa. His influence is so big that he recently hosted several 2016 GOP candidates on his show, including Carly Fiorina, Rick Santorum, and Ben Carson during their visits to the Iowa State Fair. After Mickelson defended his immigrant-slave plan, Gov. Scott Walker (R-WI) appeared on his show.