A major US conservative forum has dropped Donald Trump as a speaker, saying it was unacceptable for him to suggest that a journalist was tough on him because she was menstruating.
Mr Trump said Megyn Kelly of Fox News “had blood coming out of her eyes, blood coming out of her wherever“.
Ms Kelly challenged him on remarks he made about women during a TV debate.
RedState said Mr Trump was implying she was hormonal, though Mr Trump later denied this in a tweet.
“Re Megyn Kelly quote: ‘you could see there was blood coming out of her eyes, blood coming out of her wherever’ (NOSE),” he wrote.
A later statement from his campaign said “only a deviant” would think Mr Trump meant anything else.
Mr Trump was one of 10 Republican presidential candidates in a TV debate co-hosted by Ms Kelly on Thursday, which was watched by a record 24 million people.
Early on in the debate, Ms Kelly asked him why voters should elect a man who has called women “fat pigs, dogs, slobs and disgusting animals”.
Mr Trump joked that he only said that about TV personality Rosie O’Donnell before adding: “I don’t have time for total political correctness.”
After the debate, he took to Twitter to say Ms Kelly had “really bombed” and that she hadn’t been “very good or professional”.
He continued his attack on CNN on Friday night, saying Ms Kelly was “a lightweight” and that he “couldn’t care less about her”, before making the comment about blood.
He had been scheduled to deliver the keynote address on Saturday night at a conference in Atlanta organised by RedState, an influential conservative group.
But on Saturday, RedState chief Erick Erickson said he had rescinded My Trump’s invitation because his comments on CNN had been “a bridge too far”.
In a statement, he said Mr Trump connected with many Republicans because he is outspoken but that “there are even lines blunt talkers […] should not cross”.
“It is unfortunate to have to disinvite him. But I just don’t want someone on stage who gets a hostile question from a lady and his first inclination is to imply it was hormonal,” he added.
“There is no way to otherwise interpret Mr Trump’s comment,” he said.
Mr Erickson, a powerful conservative activist, said he had invited Ms Kelly to take Mr Trump’s place but was unsure if she would be able to attend.
Carly Fiorina, the only female Republican candidate, joined the criticism of Mr Trump, tweeting “There. Is. No. Excuse” shortly after the CNN interview.
Mr Trump’s campaign responded to RedState’s move by saying it was “another example of weakness through being politically correct”.
He is ahead of the 16 other Republican candidates in several recent polls despite making several controversial remarks since launching his president campaign.