* Dropping out or staying in the race?
* Polls dropping nationwide
* 'Kitchen summit' meeting with wife (Adds comment from voter)
By Harriet McLeod
ROCK HILL, S.C., Dec 2 (Reuters) - Herman Cain, battling allegations of infidelities, is expected to announce on Saturday in Atlanta whether he is continuing his bid for the Republican U.S. presidential nomination.
In remarks at a campaign stop in South Carolina, Cain gave no hint as to what his decision might be. He is to meet with his wife, Gloria, who has so far stood by her husband as he has tried to weather a chain of sexual allegations from several women that have included groping and a 13-year affair.
"I am reassessing because of all this media firestorm stuff," Cain told supporters in South Carolina. "Why? Because my wife and family come first. I've got to take that into consideration."
Cain's support has been dropping as he has attempted to outlast the allegations and other campaign mishaps, but the bad news is taking its toll.
A Des Moines Register poll gave him 8 percent support among Republicans in Iowa, which holds the first U.S. nominating contest of the 2012 election cycle on Jan. 3.
"The writing's on the wall," said Republican strategist Ron Bonjean. "The polling has dropped to the floor. He can no longer sustain a positive campaign with these allegations."
Cain, expected to meet with supporters in Atlanta who are gathering for his scheduled 11 a.m. EST/1600 GMT opening of his Georgia campaign headquarters, said he has to look at what happens to his campaign contributions.
"We have got to re-evaluate the whole strategy. Tomorrow in Atlanta, I will be making an announcement, but nobody's going to get me to make that prematurely," the former Godfather's Pizza CEO said.
One person close to the campaign said it is still unclear what Cain has decided to do, but the source said the campaign expects Cain to make his announcement at the previously scheduled opening of his Atlanta campaign office.
"It could be the grand closing as well as the grand opening," the source said.
A McCain supporter at the Rock Hill event, Doug Westmoreland of Clover, South Carolina, said he does not want the Cain campaign to end. "I think I live in a country where you are innocent until proven guilty," Westmoreland said.
Cain has given little sign of actually getting out of the race, although he said on Thursday he would drop out if his wife asked him to.
"I will put her first. But she is not the type to say 'You ought to get out,'" he said in an interview with the New Hampshire Union Leader on Thursday.
Cain also told the newspaper his wife of 43 years knew nothing about his involvement with, and financial support for, Ginger White, an Atlanta businesswoman who said she and Cain carried on an affair for years. He has maintained he and White were just friends and he was helping her financially.
White, 45, spoke about the relationship on MSNBC on Thursday, saying they did not have a "love affair."
"It was a sexual affair, as hard as that is for me to say and as hard as it is for people to hear it. You know, it pretty much is what it is. And that's what it was," she said.
White apologized to Cain's wife:
"My heart bleeds for this woman because I am a woman and being in a situation like this cannot be fun," she said. "And I am deeply, deeply sorry if I have caused any hurt to her and to his kids, to his family. That was not my intention."
The candidate, who led the Republican race barely more than a month ago, has also been victim of several self-inflicted stumbles.
He raised alarm among conservatives with confusing comments about abortion, and badly fumbled a question on Libya policy in a televised interview.
Cain's campaign e-mailed a fresh fund-raising appeal on Friday, saying "the only way we can gauge true support is by the willingness of our supporters to invest in this effort."
And a new "Women for Cain" web site was launched, saying Cain "has been a strong advocate for women throughout his lifetime." (Additional reporting by Ros Krasny and Sam Youngman; Writing by Steve Holland; Editing by Vicki Allen and Todd Eastham)