Rick Santorum faceplants on CNN when asked to explain how Trump's wall would stop the drug trade

Conservative CNN political commentator Rick Santorum went off on an unhinged anti-immigrant rant on Wednesday, but was ultimately unable to say how President Donald Trump's border wall would solve anything.

"The president talked about the consequences of the illegal immigrants in this country committing crimes," Santorum shouted at his colleague, former Clinton Press Secretary Joe Lockhart. "With all due respect, you can say 'it's a smaller percentage'. They shouldn't be here. What we are talking about people who are illegally in this country and they should not be here and they are doing these things."

"That's really unfair to the families affected who say, 'look, these people are here unjustifiably, they're here illegally,' not like other immigrants who are here legally," Santorum went on angrily, as host Alisyn Camerota tried to get a word in edgewise.

"How does a wall stop the heroin trade?" she finally broke in. Santorum sat stunned for a moment and began to stammer.

"Well, look, the wall is part, " Santorum mumbled. "Does it help on the margins? Maybe a little bit, you're right, most of the heroin comes through ports of entry."

"The research suggests it comes come through ports of entry through tractor-trailers and passenger vehicles," Camerota replied, shaking her head. "People who are climbing over a fence aren't lugging heroin."

"I don't think the American people need a lecture from you or from the president on what the problem is," chimed in Lockhart, noting that the number of border agents has quadrupled as immigration has plummeted. "It's a manufactured crisis for the president to get a political win."

Watch the video below.