A defiant Herman Cain tried to turn the tables on his growing legion of critics and accusers Wednesday, blasting them for allegedly engaging in gutter politics and giving no indication of any immediate intent to abandon his embattled presidential campaign.

“They have been trying to do a character assassination on me,” Cain told an enthusiastic crowd in Ohio. “They are attacking my character, my reputation and my name in order to try and bring me down.”

“I don’t believe that America is going to let that happen,” he declared.

Cain, who is dropping in Republican presidential horserace polls, urged his audience to “know the facts” and “stay informed because … stupid people are running America.”

Cain’s unorthodox campaign has been under siege in the wake of a string of accusations relating to alleged sexual harassment. On Monday, it took a new hit when a Georgia woman alleged she had engaged in a long-term affair with the former Godfather’s Pizza CEO.

“This was not a consistent love affair,” Ginger White told ABC’s “Good Morning America.” It was “on and off” for about 13 years.

Cain has denied the affair and called his relationship with White “very casual.”

Regardless, the candidate told his staff Tuesday that he was “reassessing” his campaign in the wake of White’s allegation.

On his official Twitter feed, Cain wrote, “The definition of reassess is: To consider again, esp. while paying attention to new factors. Doesn’t sound like dropping out…”

But Cain told CNN’s Jim Acosta after his remarks in Ohio that a final decision on the fate of the campaign would come within “the next few days.”

In a fundraising letter Tuesday night, Cain wrote that “a troubled Atlanta business woman used national media outlets to promulgate a fabricated, unsubstantiated story about a 13 year affair with me. I am writing you today to assure you that this woman’s story is completely false.

“I do know Ms. White. I have helped her financially at times over the past few years, just as I have helped many friends and acquaintances throughout the years. I thought Ms. White was a friend in need of a supportive hand to better her life. Ms. White has made it apparent that she was abusing the friendship.”

He added, “Let me assure you, I am not deterred.”

On Wednesday morning, White responded, “It’s very disappointing that he would call me troubled.”

“I’m only here to state the truth and what’s happened in the past,” she said.

She acknowledged that Cain has given her money. “I’ve received gifts and money for the last 2 1/2 years consistently,” she said, adding that he did not ask for anything in return.

She and Cain were in touch until last week, when there were leaks about the relationship and members of the media began to call her cell phone and family members, White said.

White said she came forward to share her side of the story.

“I can’t imagine waking up one morning and deciding to come out with this if this was not true,” she told ABC. “This has been a very difficult situation for myself, for my family and it’s nothing that I am proud of.”

“So far I have been absolutely humiliated, embarrassed,” she said.

White said she had not saved receipts and notes throughout the affair because she never planned to make the relationship public.

But, she said, Cain took her on several trips, including to a boxing match in Las Vegas.

“I can’t make this stuff up,” she said.

Asked whether his recent texts to her included requests that she not come forward, she replied, “Absolutely not. The funny thing about Herman Cain is, never in a million years did he probably think that I would speak out on this. And honestly speaking, I never wanted to.”

White said she had seen reports of several women accusing Cain of sexual harassment. For his part, Cain has repeatedly denied all of the allegations.

While her experience with him does not compare, White said, “I feel their pain.”

Two women — Sharon Bialek and Karen Kraushaar — accused Cain this month of sexually harassing them in the 1990s while he was head of the National Restaurant Association. Two other women also have said Cain sexually harassed them while they worked at the association, but they have declined to be identified.

White acknowledged she is being sued for libel by a former business partner. “There were disputes and disagreements” with the partner and the experience became emotional, she said, acknowledging that she made mistakes. White said she thought the situation had been resolved.

Asked whether she believes Cain should end his campaign, White responded, “That’s something he has to decide for himself.”

“Last night I slept very well,” she said, “telling the truth.”

A top campaign source told CNN Tuesday he expects Cain to make a decision shortly about the future of his presidential bid, based on whether fundraising dries up.

Another source familiar with internal campaign deliberations told CNN the question now is “money and support.” The source, speaking on condition of anonymity, said the already small campaign operation would likely have to lay off some staffers.

“We just staffed up some, but at a minimum it looks like [there is] no choice but to staff down,” the source said. “We are in the period of the campaign where we need to spend to perform.”

The question is, the source said, whether donors and Republicans believe Cain or his newest accuser.

The story broke Monday night when Atlanta television station WAGA aired an interview with White, who said the affair began after she and Cain met in the late 1990s in Louisville, Kentucky, where Cain was giving a talk as head of the restaurant association.

“I was aware that he was married, and I was also aware that I was involved in a very inappropriate situation — relationship,” she said.

White told CNN affiliate WSB that the relationship was sexual in nature.

White told WAGA the affair ended early this year as Cain prepared to announce his presidential bid. But she pointed to mobile phone records she said prove Cain was calling her as late as September, including one call at 4:26 a.m.

White showed WAGA some cell phone records that included 61 phone calls or text messages from a phone number she identified as Cain’s private cell phone. The station texted the number and Cain called them back.

CNN’s Alan Silverleib, Josh Levs, Kevin Bohn, Gloria Borger, Peter Hamby, Wolf Blitzer, and John King contributed to this report