Conservative phenomenon Ben Carson has refused to back down after making controversial comments comparing the United States to Nazi Germany and the Affordable Care Act to slavery in an interview with CNN's Wolf Blitzer on Wednesday.

Carson, a celebrated neurosurgeon, was asked by Blitzer whether he would amend or take back comments made during a March interview with conservative news outlet Breitbart.com. "Absolutely not," Carson responded.

"Nazi Germany experienced something horrible," Carson told CNN's Blitzer on Wednesday. "The people in Nazi Germany largely didn't believe in what Hitler was doing. But they didn't say anything? Of course not, they kept their mouth shut. The fact that our government is using instruments of government like the IRS to punish its opponents, this is not the kind of thing that is a Democrat or a Republican issue. This is an American issue ... A lot of people do not feel free to express themselves."

When Blitzer questioned him whether the comparison was appropriate, Carson argued his focus on the specific words was "part of the problem," Huffington Post reported.

"What you were doing is allowing words to affect you more than listening to what was actually being said. And that's part of the problem," he said.

"You are just focusing on the words 'Nazi Germany' and completely missing the point of what I said," Carson told Blitzer. "And that's the problem right now. That's what 'PCism' is all about. You may not say this word regardless of what your point is because if you say that word, I go into a tizzy."

Additionally, the 63-year-old also refused to retract last year's comments in which he described Obamacare as the "worst thing that has happened in this nation since slavery," according to CNN.

"Slavery was a horrible thing and affected many people in horrible ways, some of those effects still present today. So, no, it is not the same as slavery," he said of Obamacare on Wednesday. "However, what needs to be understood here is that the way this country was set up, the people -- we the people were set up at the pinnacle of power in this nation."

"The government is supposed to conform to our will," he added. "By taking the most important thing you have, your health and your health care, and turning that over to the government, you fundamentally shift the power, a huge chunk of it, from the people to the government. This is not the direction that we want the government to go in this nation."

Asked whether other critical events in U.S. history that have gripped the nation, such as the terror attacks of September 11, 2001, or the Great Depression, would better qualify as the worst thing to happen to the country since slavery, Carson replied, "That's not the point."

"I think it's nonproductive to get into worse than this or worse than that, or maybe it's better than this or better than that. That's not the point of what I'm saying. The point is a major fundamental shift of power has occurred," from the people to the government, and "if we continue down that road the United States of America becomes something very different than it was intended to be."

Meanwhile, Carson is considering a 2015 presidential run after a CNN/ORC poll out this week found Carson unexpectedly taking second place in a crowded field of potential 2016 GOP candidates.

The interview can be watched here.