It is safe to say that no other Republican on the campaign trail this year — or ever — has begun a speech with the phrase “Awww, shucky ducky!” the way Herman Cain did this year to the utter delight of his audience, which responded with wild applause.

Cain, who is black, also has a penchant for gold ties because, as he explains with flirtatious flair, “that color happens to look good against this beautiful dark skin.”

No candidate today is as daring as Herman Cain when it comes to charming an audience with silky silliness. His humor has distinguished him from his rivals, lending an air of folksiness and authenticity, a visceral contrast to his cooler, more staid rivals, especially Mitt Romney and President Barack Obama.

Not all of Cain’s attempts at comedy succeed, however. Last weekend, he tried to back away from what he called a joke about illegal immigration: that his policy would include an electrified border fence to kill anyone who tried to cross.

The moment illuminated one of the main concerns about Cain: He could have a hard time being taken seriously, at least to the degree that he uses sarcasm and laughs to divert attention from what for another candidate could be disqualifying gaps in knowledge and experience.

And while his casual style of racially inflected humor works to ingratiate him with mostly white audiences at campaign rallies, it has angered some black critics, who believe he plays on age-old stereotypes.

He has no qualms, for instance, about playing off black cliches: Should he become president, his Secret Service codename should be “Cornbread,” he wrote in his memoir, “This is Herman Cain! My Journey to the White House.” Cain’s traveling aide, Nathan Naidu, already refers to him as Cornbread on the internal campaign schedule. (Why? Cain says he just loves cornbread.)

Those kinds of comments have drawn criticism from the likes of academics like Cornel West and entertainers like Harry Belafonte, who called Cain “a bad apple.”

Of particular concern, some say, is how he seems to make a parody of black vernacular and culture.

“It makes the hair on my neck stand up,” said Ulli K. Ryder, a visiting scholar at the Center for the Study of Race and Ethnicity in America at Brown University. “The larger issue that a lot of people have, and I certainly have, is that he uses a certain kind of minstrelsy to play to white audiences. Referencing negative stereotypes in order to get heard to a white audience in the 21st century is really a problem.”

Take “shucky ducky.”

“It’s a nonsensical thing, down-home Southern black vernacular,” Ryder said. “It’s coded as a black vernacular and it’s uneducated black vernacular, so I find it really interesting that he would reference that, seeing as he is not that.”

Nonetheless, some strategists say that Cain has succeeded at being the everyman candidate, much like Mike Huckabee, whose clever quips helped him win the Iowa caucuses four years ago.

Cain “has done a good job of positioning himself as a ‘regular folks’ kind of guy,” said Steve Schmidt, a Republican consultant.

When a politician is trying to elicit laughs, the stakes are high.

“The drawback is that there is a line with humor, and every joke is a risk,” said Landon Parvin, who has written humorous speeches for several Republican presidents. “Often you don’t know where that line is, and if you cross it, everything comes down on your head.

“You want to project the humor of good-naturedness,” Parvin added. “That’s what’s important for politicians. Back in the Reagan White House, the easiest way to get on the evening news was to do a one-liner that had some substance to it. If you can crystallize your humorous point in a serious way, that’s very effective.”

In contrast, in the days after Cain’s comments about killing people with an electrified border fence, Cain repeatedly felt the need to apologize, which was ultimately a distraction from the substance of his larger immigration platform.

“Mea culpa, mea culpa, mea culpa,” he said.

That Cain, a former executive at Godfather’s Pizza and Burger King who has never held public office, writes his own rules has been evident since the beginning of his campaign for the Republican nomination in the spring. Even as he has surged in popularity recently after winning the Florida straw poll and drawn increased interest for his “9-9-9” economic plan, which proposes a drastic reworking of the tax code, Cain has largely eschewed the campaign trail in favor of going on a tour to promote his memoir.

And he has hardly changed his style. At the Values Voter Summit last week in Washington, he received rave reviews. A snippet of the speech was long on attitude, short on policy prescriptions: “Why are you running for president? To be president!” Cain thundered in his booming baritone. “What did I miss? I’m not running to go to Disneyland. America has problems. I’m a problem solver. That’s why I’m running.”

Just then, someone in the crowd screamed, “We love you, Herman Cain!”

He continued, “My challenge to you is to stay informed because we are up against a lot of stupid people in America who do not have a clue.”

While “stupid people in America” might not have a pleasant ring to it, the phrase certainly elicited a great reaction from the crowd. (Presumably, the “stupid people in America” were not there.)

“That guy played the audience like a violin,” said Dick Bott, an influential conservative radio broadcaster who owns 89 stations, mostly in the Midwest, who was in attendance. “Herman Cain seems to be the kind of person who is comfortable with his own thoughts. He was expressing himself in a very major speech to that base of voters with the confidence that didn’t require being careful about everything he said.

“It’s hard to imagine anyone who connects with an audience the way he does,” Bott added.

In the fantasy debate of the humorist Parvin’s dreams, the freewheeling Cain would be matched up with his stylistic antithesis, the professorial Obama.

“I know who would win on personality,” Parvin said. “Who would win on substance; that might be a different story.”