Today on his nationally syndicated radio show, he called The Nation's investigation, titled, "Lou Dobbs, American Hypocrite," "an attack piece" filled with "outrageous claims."
Dobbs went head-to-head with reporter Isabel Macdonald about her assertion that he hired illegal immigrants to maintain his family's homes and horses.
Their conversation quickly turned into a confrontation:
Dobbs: "Did you say that I hired or my firm hired illegal immigrants?"
Macdonald: "I am saying that for years, undocumented immigrants looked after your show jumping horses, and for years, they looked after the grounds at your West Palm Beach estate in Florida. This article is fact-checked 100 percent, it is legally vetted."
Dobbs hammered Macdonald with questions but seemed loathe to offer any explanations himself. He suggested that if the workers he hired were illegal immigrants, he didn't know that.
"I had been told that they were absolutely legal," he said. "And you were told the same thing ... and you didn't mention that in your piece."
The back-and-forth ended abruptly. As Dobbs tried to dismiss Macdonald from the program, she said, "Your listeners deserve better. I'm saying your listeners deserve to know the truth."
His response: "Are you saying they deserve better than going to TheNation.com? Because that's the last thing I think they should do. ... Let's try focusing on truth and reality and straightforwardness, OK?"
For her Nation piece, Macdonald interviewed at least five undocumented immigrants who did work for Dobbs. Some were brought on to help take care of the horse Dobbs' 22-year-old daughter Hillary used in her professional career as a show jumper.
"At the very same time Lou Dobbs was talking on CNN about the possibility of felony charges for employers who hire undocumented workers, there were undocumented workers caring for his $1 million show jumping horses and undocumented workers caring for the grounds of his estate in West Palm Beach," Macdonald told ABC News.
One man named Rodrigo Ortega told Macdonald about meeting Dobbs, who introduced himself in Spanish as "Luis." Ortega said that Dobbs "knew very well that the majority of us didn't have papers," but that "was never a problem."
Lou Dobbs After CNN
Dobbs, 65, abruptly left CNN in November 2009. He joined the network when it launched in 1980 and, in his later years there, used his nightly program, "Lou Dobbs Tonight," as a soapbox for rants on illegal immigration, federal spending and President Obama.
For years, in his "Broken Borders" segment, Dobbs warned of dangers he said illegal immigrants caused. He ran a false report on the number of leprosy cases in the United States allegedly caused by Mexican immigrants. He also railed against many plans that called for a path to legalization for illegal immigrants.
Protests and campaigns were launched to get CNN to "dump Dobbs."
Despite the furor, Dobbs said his next move after he left CNN might be into the political arena.
"I was thinking about running for office, thinking about politics," he told ABC News' "Nightline" in January. "A number of people have asked me to think about president, Senate and, as I have said, it's flattering. It's heavy stuff, and I would be lying if I told you I wasn't enamored at various junctures of my thinking with the idea."
ABC News' Melinda Arons contributed reporting.