"When you look at this, I think that there's been such a hard push on this. The reason they're called 'dreamers' because that's the most sympathetic term that could be apply applied to people," the Iowa Republican said in an interview on CNN's "New Day."
"Among all of these dreamers, there are some awfully bad people. And these dreamers go on up to the age of 37 or 38 or maybe older. And that's if they tell the truth."
President-elect Donald Trump has said he will terminate DACA, or the Deferred Action for Childhood Arrivals, an executive action signed into law by Obama in 2012 that gives some undocumented immigrants an exemption from deportation and a renewable two-year work permit. Among the guidelines, the policy states that applicants must have come to the United States before they turned 16 years old, must have been in the States since June 15, 2007, and cannot have been convicted of certain crimes.
Pressed for an example of those "awfully bad people," King didn't offer any specifics, but pointed to his experience from trips to the border where he said he'd seen "young men" smuggling drugs.
"I've spent a fair amount of time down at the border. I've been down there and helped arrest people that are smuggling drugs in," he said. "I have watched as these packs of marijuana are on the backs of young men that are walking across the border."
"You think those drug traffickers are what are referred to as the dreamers who were brought here against their will as minors, and now go to school here and have jobs?" host Alisyn Camerota asked.
King pushed back. "Wait, wait, wait -- this definition of about 'against their will -- that's a made up term," he said.
"Did any of those little kids say I didn't want to come here? Or did any of them that came in the day before they turned 18, they qualify too, did they say I was brought here against my will? No. Some of them are walking across the border on their own, lots of them," he said.
"They know what they're doing, it's not against their will," King added. "And they came here to live in the shadows. So, if we enforce the law and they live in the shadows, that's what they came here to do."
Camerota pressed King on whether he would support allowing children under age 10, for example, to stay. "Did they come of their own free will?" she asked.
"Let's ask their parents. Will those children point to their parents, and tell us you really need to enforce the law against my parents? Because they know what they were doing when they caused me to break the law. I don't think we've thought through this very well," he answered.
King explained that "I don't want to let this go because somebody's heart got a little softer than it was before the election."
The Iowa representative -- one of the most outspoken voices on immigration in the Republican conference -- also staked out an aggressive position on Trump's proposed border wall, saying he wanted concrete wall with extensive security features covering the entire U.S.-Mexico border.
King said that proposals for a "virtual" wall based on a mixture of fencing, technology, and funding increases -- something Rep. Dennis Ross (R-FL) pitched to Bloomberg News -- would not be acceptable.
"I would say to my friend Dennis, that's, you know, that's news speak. When you say a wall's not a wall, then what is anything anything?" he said. "When you say a wall, you mean a wall. You want to build a fence, you say fence. You don't use it a euphemism for a virtual -- say, surveillance from hot air balloons that are floating over the border."
King called for a wall "made out of concrete. And, I'm calling upon President-elect Trump to not just settle for a wall, let's build a fence, then a wall, then a fence, so we create two no man's lands, one on either side of the wall. When we pick people up there they don't really have an excuse. They weren't out there picking mushrooms."