An unapologetic and defiant Herman Cain suspended his presidential campaign on Saturday, pledging that he “would not go away” even as he abandoned the Republican presidential race in the face of escalating accusations of sexual misconduct.

“As of today, with a lot of prayer and soul-searching, I am suspending my presidential campaign,” Mr. Cain said at a rally in Atlanta, surrounded by supporters chanting his name. “Because of the continued distractions, the continued hurt caused on me and my family, not because we are not fighters. Not because I’m not a fighter.”

In suspending his candidacy, as opposed to saying that he was ending his bid, Mr. Cain, according to campaign finance lawyers, maintains an ability to accept money to pay for his campaign so far and potentially to finance the new venture that he called his Plan B: to travel the country promoting his tax and foreign policy plans.

The collapse of Mr. Cain’s campaign came as a new Des Moines Register poll showed that his supporters appeared to be gravitating toward Newt Gingrich, the former House speaker. According to the poll, Mr. Gingrich is backed by 25 percent of likely Republican caucusgoers, followed by Representative Ron Paul of Texas with 18 percent and Mitt Romney with 16 percent. The poll was conducted before Mr. Cain suspended his campaign, and it showed him with the support of just 8 percent of respondents, a sharp drop from previous polls.