On Sunday, Herman Cain was blindsided when Politico published an investigation into sexual harassment allegations made against him when he was CEO of the National Restaurant Association.

The Republican presidential candidate denies any wrongdoing, but his responses to the story have been inconsistent, and some public relations experts say he is doing a bad job at damage control.

Watching your initial reaction on camera of a reporter confronting you on the allegations was the definition of a 'deer in headlights,' Ronn Torossian, the CEO of 5W Public Relations, wrote in an open letter to the Georgia businessman-turned-politician. You looked lost and confused.

Torossian was referring to a video of Politico reporter Jonathan Martin approaching Cain as he left a CBS interview on Sunday and asking for a response to the allegations that he sexually harassed two female National Restaurant Association employees in the late 1990s and that those employees received payouts to leave the organization and not talk about the incidents.

Have you ever been accused, sir, in your life of harassment by a woman? Martin asks in the video.

Cain glares at Martin for a minute before responding, Have you ever been accused of sexual harassment?

That exchange happened 10 days after Politico says it first contacted the Cain campaign for comment, but Cain appeared caught off guard.

Inconsistent Responses

Since Politico published its investigation, Cain has responded in a variety of ways.

At first, he said he had no recollection of the allegations, telling a reporter that he has had thousands of people working for me at different points and that he could not comment until I see some facts or some concrete evidence.

After Politico told him the names of the two women who accused him of sexual harassment, Cain said he was not aware of any settlements. But later, he said that he was aware of the settlements but that the allegations had been false, because he had never sexually harassed anyone.

He shifted his story again Monday night, saying he remembered the specific incident that one of the two women had complained about -- he had raised his hand to his chin to illustrate a person's height and told the woman that she was the same height as his wife -- but that he didn't recall any other incidents.

Then, on Tuesday, he did recall something else, although he didn't remember what that something else was.

There were a couple of other things in there that I found absolutely ridiculous, he told CNN reporter Robin Meade. I don't even remember. They were so ridiculous, I don't remember what they are.

When Meade asked him how he could know the accusations were ridiculous if he didn't remember what they were, Cain responded, The reason I forgot them is because they were ridiculous. I dismissed them out of my mind. I said if she can make that stick and call that sexual harassment, fine. But it didn't stick, OK? So I don't remember what they were. The only thing that I remember is the one gesture that I made, talking about the height.

Cain's spokesman, J.D. Gordon, has also been evasive in responding to the story, refusing to give a straight answer when Fox News host Geraldo Rivera asked whether any women working under Cain had ever been given financial settlements. Afterward, Rivera called that a recipe for disaster.

In an effort to explain the discrepancy between his initial statement that he didn't recall any settlement and his subsequent statement that he did, Cain told Meade that the accusations had been resolved with a separation agreement, which is legally distinct from a settlement -- a semantic issue more than a substantive one, his critics say.

A Self-Created Problem

All of these twists in his response to the Politico story have made it a bigger public relations problem than it would have been otherwise, Torossian said in his open letter.

The truth will come out, so tell it, he wrote. The accusations may indeed be false, but if agreements were signed, something happened, even if it wasn't harassment. Get out in front of the story and tell the truth -- exactly what you know and all of what you know to defuse reporters and take the wind out of their sails. Do it now -- this story won't go away. Tackle it aggressively and do so immediately. You won't be able to outwork this issue or change the topic.

After that, Torossian said, Cain should reframe the debate and go for the jugular, turning the attention to his opponents' deficiencies instead of his own.

Once you've told the truth -- all of it, so there's nothing more to tell or investigate -- flip the script and start nailing your opponents on the weaknesses of their policy, Torossian wrote. Do your own opposition research. If you're not doing it, start. This is when the game of politics starts getting dirty. Make sure it's straightforward and truthful information that deals with policy and character issues.

The hoopla surrounding the Politico story has, fairly or not, added to the perception that, while Cain may be a brilliant businessman, he is out of his league on the national campaign trail.

His campaign has had to beat back repeated criticisms of disorganization and lack of professionalism, and even though he has outpolled Mitt Romney for more than a month now, he still faces skepticism about his ability to sustain his lead through next year's primaries and caucuses with minimal on-the-ground campaign infrastructure.

Those criticisms are even coming from within Cain's own party.

Had Cain immediately acknowledged the two settlements, noted that they were small and based on unproven charges, and explained his side of the story, I and others probably wouldn't be writing about them today, Kyle Wingfield, a conservative columnist for the Atlanta Journal-Constitution, wrote, noting that Cain has run largely on his credibility and authenticity. But for whatever reason -- because his advisers gave him bad advice, because he thought he could put a lid on the story with a less-complete explanation, because he's so convinced of his innocence in the cases -- he didn't do an adequate job.

A Campaign Weakness?

That lack of polish in responding to the kind of allegations that presidential candidates have come to expect is what makes Wingfield doubt that the presidency could be the first elected office a candidate had ever won, as it would be for Cain.

Even Republican strategist Karl Rove, a top adviser to former President George W. Bush, said that with his uneven responses, Cain had backed himself into a corner that he would only be able to escape if the National Restaurant Association agreed to release details of the harassment investigations.

He's not denying, but he ain't responding, and that's not the best place to be, Rove told Fox News on Monday. If these allegations are not true, say they aren't true and put it behind you. If not, better get everything out sooner rather than later because in a situation like this, if there is something there, that something's going to come out.

Cain should be prepared for things like this because he's a serious presidential candidate, Rove said. We want our presidents to be as far above reproach as possible.

The Politico story has brought Cain's campaign to a critical juncture. If the sexual harassment allegations blow over and he wins some of the early voting states next year, like Iowa or South Carolina, Cain may have the last laugh. But if he doesn't stanch the bleeding from the Politico story soon, Torossian wrote, his campaign could be dead by next weekend.