A Look Back At a Few Times Donald Trump Said ‘You’re Fired’

— -- Republican presidential candidate Donald Trump is standing by his campaign manager Corey Lewandowski, who was charged with simple battery against a reporter on Tuesday.

“‘Corey, you're fired,’” Trump said Tuesday in Wisconsin. “I can't do that.”

Lewandowski has not entered a plea, but the Trump campaign said he intends to plead not guilty. The campaign said he was "absolutely innocent" of the charge and Trump threatened legal action regarding the allegations.

But those two words -- “you’re fired” -- are part of why Trump is famous: Before he became the frontrunner for the Republican presidential nomination, the New York businessman was the star judge of the long-running NBC reality TV show, “The Apprentice.”

On the show, contestants put their business skills to the test and the weakest links were eliminated when Trump uttered his famous catchphrase.

Angie McKnight, a contestant from season three, said in an interview with Cosmopolitan magazine that her experience getting fired from Trump on the show was, “brutal,” “nasty,” and made her lose “any little bit of respect” she had for Trump.

“When he fired me, it was awful. It was a horrifying experience,” McKnight told the magazine. “He repeatedly called me a loser, said, ‘You choked, admit it,’ and badgered and badgered and badgered me. It was really nasty and unnecessary.”

But Trump has carried out only a few firings during his presidential campaign so far.

His longtime political adviser, Roger Stone, was fired in August 2015 for “wanting to use the campaign for his own personal publicity,” a Trump campaign spokesperson said in a statement provided to ABC News.

(Stone, however, refutes the Trump campaign, saying he quit over a disagreement with Trump about his feud with Fox News host Megyn Kelly).

Sam Nunberg, an adviser to the GOP frontrunner, was fired by Trump not once, but twice.

Nunberg was first fired by the campaign in early 2014, after BuzzFeed published the article “36 Hours on the Fake Campaign Trail with Donald Trump.” The Trump campaign held Nunberg responsible for the unflattering profile piece because he pushed for Trump to do the interview with Buzzfeed. But the adviser claimed he resigned from the campaign immediately after it was published.

Trump hired him as his presidential aide again in August 2015, then fired him after old, controversial Facebook posts from Nunberg’s personal account were unearthed. Nunberg said he was "shocked" at the report and "didn't recall" the posts.

Although on “The Apprentice,” Trump appeared to relish firing contestants -- even firing nearly the whole boardroom in one episode -- Trump said that wasn’t the case.

"I do have a heart, and I don't like firing people," he said in a 2012 interview with ABC’s “20/20.” "I usually like to do it very, very soft, softer than (on the) 'The Apprentice.'"

But, he added: "If somebody does something bad, if there's theft involved, if there's good reason, I do it very much like 'The Apprentice,' if not even worse.”