11/09/2011 05:43 EST | Updated 01/09/2012 05:12 EST

Besieged Cain on the hot seat amid sexual harassment allegations at GOP debate

WASHINGTON - Herman Cain complained after the last Republican presidential debate that his opponents for the nomination unduly targeted him.

It's probably safe to surmise that he ain't seen nothing yet.

This year's spate of Republican presidential debates have already proven to be sizzling verbal boxing matches, and that was before one of the frontrunners was at the centre of a lewd sexual harassment scandal.

Cain, the former pizza executive who once headed the National Restaurant Association, is facing allegations from four separate women that he sexually harassed them in the 1990s as he helmed the trade group.

Questions about those allegations have been deemed fair game by the debate's organizers even though it's meant to focus on the economy. While it wasn't clear whether the debate moderator will ask any direct questions about the allegations, there's little doubt Cain's fellow candidates will pick away at him during the Michigan showdown.

"It's going to be the most volatile issue to come up, and they will press him to give fuller answers than he has so far," Cal Jillson, a political scientist at Southern Methodist University in Dallas, said Wednesday.

"It will be fascinating to see how other candidates handle him because they've just begun to push Cain off the cliff on this matter. It's eating him alive and it's not just Cain who can't get the media to pay attention to other issues, it's the other candidates too."

Indeed, some rivals for the nomination have said this week they're troubled by the allegations and how it's dominated the Republican race.

"Only Herman Cain can address the issues before him," Jon Huntsman told The Associated Press. "In the meantime, it's sucking all the oxygen out of the room, depriving the people of this country from a conversation about the issues that really do matter."

Mitt Romney, the former governor of Massachusetts who's tied with Cain atop the Republican field, said he's disturbed by the fact that four women have levelled sexual harassment allegations against the 65-year-old Georgia businessman.

"I don't want to suppose truth or lack of truth," Romney told ABC News. "I just think it's important to recognize that a number of women have come forward with concerns; this woman's charges are particularly disturbing and they're serious."

Sharon Bialek, a 50-year-old Chicagoan, held an explosive news conference on Monday to allege that Cain pushed his hand up her skirt and attempted to shove her head towards his crotch after she approached him in 1997 about getting her job back at the restaurant association. When she complained, she alleges he replied: "You want a job, don't you?"

Inspired by Bialek's public statements, a previously unidentified accuser also came forward to reveal her identity. Karen Kraushaar -- like Bialek, a registered Republican -- said she'd welcome a joint news conference during which all four victims detail their allegations.

Bialek said on Wednesday she's all for the idea, and praised Kraushaar, now an employee at the Internal Revenue Service, for coming forward. Jillson predicted Kraushaar won't be the last.

"These things don't go away; more and more details tend to emerge and people tend to start talking," Jillson said. "I can't see how he doesn't succumb to this soon."