It might as well be Joe Biden’s campaign slogan. It’s a phrase he loves to use, one that channels indignation, a bit of an eye roll and a decent dose of macho bravado.

C’mon, man!

There are many Bidenisms, which have become a running joke among those who follow him closely. “Folks!” is the word that starts most sentences, and “Not a joke!” is the phrase that ends them. He’ll pull out “my word as a Biden” and “God love ’em,” and he almost literally uses “literally” more than most other words.

“Here’s the deal,” he says to emphasize a point. “The fact of the matter is,” is the way he starts another. “Look!” he often shouts, urging his audience to see things the way he does.

But if those are verbal tics, “C’mon, man” represents more in this campaign, imbuing a candidate who can meander rhetorically in sometimes pointless directions with a pithy sense of frustration and urgency.

It suggests disbelief that the country elected Donald Trump.

C’mon, man!

It rallies sentiment that the country is better than it is being represented on the world stage.

C’mon, man!

And it seeks to deflect questions about Biden’s own foibles, often with the accompaniment of a wagging finger or a shake of the head.

C’mon, man!

During a CNN interview that aired Friday, he used the phrase at least four times. Why wasn’t he more forceful in the debate? “C’mon, man.” Hasn’t President Trump used his tactics to get NATO to pay more? “Oh, give me a break. C’mon, man!” Should he contrast himself more with his Democratic opponents? “C’mon, man.”

If Sen. Kamala D. Harris (Calif.) could get the better of him in a debate, couldn’t Trump?

“Everybody knows who this guy is,” he said of the president. “C’mon, man. Come on.”

Biden’s phrase can quickly signal dismissiveness, annoyance, sarcasm or a certain willingness to use words that seem gendered, none of which are sure winners for a candidate trying to attract voters. But it also showcases his folksy plain-spokenness, grounding Biden’s campaign in a short bumper-sticker phrase that sounds precisely how the everyman he claims to represent would talk.

“Joe Biden is today who he was 40 years ago. He’s an Irish Catholic who grew up in a solidly middle-class house,” said Dick Harpootlian, a South Carolina state senator who has known Biden for decades. “He’s not going to speak in iambic pentameter. ‘C’mon, man’ is what you say.”

Harpootlian said there are other phrases that some might use before less family-friendly audiences. But he says Biden’s phrase — “as coarse as you’re going to get from him” — is a signal for supporters that he is tough.

“I think all of us want to hear him say ‘C’mon, man’ to Trump on a debate stage in the fall of next year,” he said. “He understands this is not going to be Marquess of Queensberry rules. He knows this is a street fight, and that’s from whence he comes.”

His use of the phrase, aides suggest, is not strategic but simply reflexive, one of the go-to lines that pops into his mind. It does not appear in prepared speeches and typically gets injected extemporaneously.

Timothy McCarthy, a historian of political movements who teaches at Harvard University’s Kennedy School of Government, called Biden’s words a “kind of blue-collar colloquial way of talking.”

“ ‘C’mon, man’ is part of that, I think, for him, where he expresses his exasperation,” McCarthy said. “Sometimes one can only muster an exasperated colloquialism to express feelings of outrage — when the alternatives would only be more profane.”

But the phrase also conjures a macho sensibility, making it potentially fraught as Biden competes against six women at a time of #MeToo activism and in the aftermath of criticism that his touchy style has made some women uncomfortable. McCarthy said a similar phrase, “you guys,” can be grating to a mixed audience.

“It has actually a little bit more meaning in this political climate where Biden is subject to critiques about the different ways he addresses and even touches or navigates space with women as opposed to men,” he said. “All language is contextual. So when Biden uses the phrase ‘C’mon, man,’ while perhaps innocent in intent, it takes on a meaning that can be problematic for him, particularly when he’s running against a bunch of in­cred­ibly qualified women. The meaning of that phrase for him, and for us, may have shifted.”

More than a matter of political correctness, McCarthy said, it’s a matter of political savvy.

Others, however, might find it comfortably familiar.

The phrase, frequently shouted on a football field or basketball court, has been injected wholesale into popular culture. It is a regular segment in ESPN’s “Monday Night Football” coverage, where the anchors show moments from the past week they found particularly objectionable. There is a “C’mon Man” line of Cajun seasoning from a Texas-based company run by former NFL running back Charles Alexander. It was the title of a 2012 movie chronicling the rise and fall of a stand-up comedian.

For Biden, the phrase could have its foundation in his relationship with former president Barack Obama, who is known for his late-night sports-watching.

Obama’s campaign ran ads against Mitt Romney in 2012 pointing out that the Republican presidential nominee had two degrees from Harvard but would cut education funding. “C’mon, man!” the narrator said.

While campaigning in 2016, Obama often used the phrase to illustrate his exasperation with the public dialogue, the rise of Trump and Trump’s claims to represent middle-class Americans. It is unclear whether Obama influenced Biden or the other way around. But Biden has certainly carried on the tradition.

In 2016, he talked of hearing in the 1980s how “Japan was going to eat our lunch. . . . C’mon, man!” A few months ago, he played down the geopolitical threat posed by China. “China’s going to eat our lunch?” he asked a crowd in Iowa City. “C’mon, man!”

During an exchange in Iowa with reporters last month, Biden used it to demonstrate his willingness to compromise and work within the system of government.

“This idea that we’re going to go in and say: ‘Okay, we’re just going to do this or that. We’re not going to consult,’ ” he told reporters in Iowa. “C’mon, man. That’s not who we are. That’s not America.”

In 2017, he used it against the man he hopes to defeat in November 2020.

“Look. He’s going to be 75 years old,” he told Terry Gross of NPR’s “Fresh Air.” “C’mon, man. This is not an ideal age to run for anything.”

Biden, who went on to say age alone should not be disqualifying, is 76.