Cain Says He Won’t Quit GOP Race, Denies New Allegations

A defiant Herman Cain declared today he would not drop his bid for the Republican presidential nomination in the face of allegations of inappropriate sexual behavior. 

Cain says it "ain't gonna happen."

Cain denied anew that he had ever behaved inappropriately and said the alleged incidents "simply didn't happen." He said he would be willing to take a lie detector test if he had a good reason.

Earlier in the day, Cain sought to undercut the credibility of the latest woman whose accusations are threatening his Republican presidential campaign. At the news conference, Cain said he doesn't ever know Sharon Bialek  who says Cain reached under her skirt when she met with him in Washington about getting work.

His chief rival, Mitt Romney, weighed in for the first time, calling the allegations "particularly disturbing."