Picking up a cupcake with his signature tax plan 9-9-9 etched in the icing, Herman Cain exclaimed, “How sweet it is”—even as he tackled uncomfortable questions about sexual-harassment allegations before a National Press Club luncheon audience on Monday. Nothing, it seems, can rattle Cain’s trademark joviality.

The Republican presidential frontrunner said his surge in the polls has acquainted him with what it feels like to be near to the top, and thanks to “today’s big news story,” he said, I really know what it means to be on top.”

Cain was referring, of course, to the Politico story saying that two female employees at the National Restaurant Association had accused him of sexual harassment when he headed the trade group in the late 1990s. That was a significant admission for a campaign that had insisted the night before that Cain was only “vaguely” aware of the allegations.

The candidate continued to maintain that he didn’t know how much the women had received in settlements over his alleged misconduct when they left the organization. But he did it in a breezy style: “I hope it wasn’t for much because I didn’t do anything.”

Indeed, he initially denied knowledge of any settlement, declaring, “I’ve never sexually harassed anyone, and the accusations are totally false.” He did acknowledge that he was accused of sexual harassment—“falsely accused I might add”—and said that he recused himself from an internal investigation that he contends found the charges baseless.

“I’m not going to chase anonymous sources,” Cain said When the AP’s Mark Hamrick asked whether he or the restaurant group would be releasing more information “to further shoot this down,” Cain responded: “No, there’s nothing to shoot down… Enough said about the issue, there’s nothing there to dig up.”

[In a taped interview with Fox's Greta Van Susteren, Cain said he recalled one encounter with a female employee: "She was in my office one day, and I made a gesture saying—and I was standing close to her—and I made a gesture saying you are the same height as my wife. And I brought my hand up to my chin saying, 'My wife comes up to my chin.'" At that point, Cain gestured with his flattened palm near his chin. "And that was put in there [the complaint] as something that made her uncomfortable," Cain said, "something that was in the sexual-harassment charge." Did the woman complain at the time? "I can't recall any comment that she made, positive or negative," Cain told Van Susteren.]

Asked if he thought the story might have been planted by a rival GOP campaign, Cain responded with the confidence of a man who now tops the polls nationally. “I told you this bull's-eye on my back has been getting bigger,” he said. “I have no idea of the source of this witch hunt.”

If he’s bothered by the current media frenzy, he isn’t letting on, attempting to turn everything into a source of amusement. His entourage is becoming increasingly well known, with chief of staff Mark Block, best known for taking a drag on a cigarette in a Cain ad, revealing that he was asked to autograph a cigarette on his way into the press-club luncheon. Rich Lowrie, who Cain introduced as the “co-architect” of his 9-9-9 plan, was brought to the microphone to say it is designed to “generate the most revenue and do the least amount of damage to the economy.”

Asked for his views on the state of race relations, Cain said he doesn’t think that opposition to President Obama has anything to do with his race, that it’s based on “bad policy.” He accused the administration of playing the “race card” and the “class-warfare card” and that “as a result, there is more racial tension than there has been.”

Cain observed that the Tea Party has been painted as a racist organization, but that he started speaking at Tea Party rallies in 2009 “before it was cool, and the rallies have only gotten bigger.” Addressing the theory that he’s doing so well in the polls because white Republicans are trying to send a message that they’re not racist, he exclaimed: “This many white people can’t pretend that they like me.”

A message of unity carried Obama to the White House, and now Cain has retooled that message in a way that combines a business leadership with motivational zeal and just enough religiosity so that it seemed perfectly natural for him to conclude his speech at the National Press Club by belting out “Amazing Grace.” Cain may well be the first White House contender in the maelstrom of a potential scandal to have broken into song.