Forty percent of Republicans have a less favorable view of Herman Cain after watching the press conference in which Sheila Bialek accused the GOP presidential candidate of groping her in a car, according to a Reuters-Ipsos poll released on Tuesday.

Thirty-nine percent of Republicans polled said they believe the allegations against the candidate are true. On Tuesday Cain accused Bialeck of lying, and said he doesn’t “remember knowing her.”

While recent polls show that Cain continues to match up well against his GOP rivals, a Gallup poll released on Tuesday showed Cain’s “positive intensity score” has plummeted in the weeks since the sexual harassment allegations were first made public.

Bialek is the fourth woman to accuse Cain of sexual harassment but the first to do so publicly. Cain has strongly denied the accusations, and his campaign responded by attacking Bialeck’s credibility on Tuesday, saying she has a “long and troubled” history.