Debate moderator was menstruating comment haunts Donald Trump

Washington - Donald Trump has been disinvited from a Republican party event on Saturday over a suggestion that a debate moderator was tough on him because she was menstruating.

The off-handed comment unleashed a new storm of criticism of Trump and put him in spin control mode as he sought to nuance his remark.

The bombastic billionaire came under fire from his own party after a particularly crude accusation that Fox News anchor Megyn Kelly, one of the moderators at Thursday's Republican presidential debate, had singled him out with rough treatment at that forum.

Trump had already called out the station's moderators for asking "unfair" questions. But he turned up the tone on Friday when he told CNN that Kelly "is just somebody I didn't have a lot of respect for".

"You can see there was blood coming out of her eyes, blood coming out of her wherever," he continued.

By Saturday, Trump's invitation to a grassroots Republican event in Atlanta had been rescinded.

"As much as I do personally like Donald Trump, his comment about Megyn Kelly on CNN is a bridge too far for me," said conservative pundit Erick Erickson, editor of RedState blog and organiser of the event. Trump was to have spoken at it.

"His comment was inappropriate. It is unfortunate to have to disinvite him," he continued.

Carly Fiorina, the only Republican presidential candidate, tweeted: "Mr. Trump: There. Is. No. Excuse."

She later added "I stand with @megynkelly."

Trump meanwhile backtracked from the comment, stating that he was not referring to any one particular body part.

"Re Megyn Kelly quote: "you could see there was blood coming out of her eyes, blood coming out of her wherever" (NOSE). Just got on w/thought," Trump tweeted.

"So many 'politically correct' fools in our country. We have to all get back to work and stop wasting time and energy on nonsense!" he tweeted.

A staggering 24 million viewers tuned in to Fox News to watch the debate, and Trump was clearly a main factor.

In a brutal tweet on Friday he let the broadcaster know it.

"@FoxNews you should be ashamed of yourself. I got you the highest debate ratings in your history & you say nothing but bad," Trump tweeted to his 3.5 million followers.

The Republicans will host at least eight more debates as the party whittles down its broad field and determines its flagbearer to go up against likely Democratic nominee Hillary Clinton.

In the meantime, Trump will be sitting out Saturday's grassroots event.

".@redstate I miss you all, and thanks for all of your support. Political correctness is killing our country. 'weakness,'" he tweeted.