Hillary Clinton campaign chairman unloads on Donald Trump on Twitter

Fact-checkers have refuted Hillary Clinton's claim that Donald Trump is becoming the "best recruiter" for the Islamic State of Iraq and Syria (ISIS), but her campaign chairman refuses to walk back her words, as Trump continues to call Clinton a liar and insist on an apology.

John Podesta went on a lengthy Twitter tirade Monday evening defending the Democratic candidate's claim.

But this doesn't support what Clinton said, exactly. Clinton's claim at Saturday's Democratic debate was this: "They are going to people showing them videos of Donald Trump insulting Islam and Muslims in order to recruit more radical jihadists."

None of the experts Podesta cites talk about actual ISIS videos featuring Trump - they just broadly say that Trump's rhetoric plays into ISIS' message about a war with the West.

Trump has demanded an apology from Clinton, to which her campaign responded, "Hell no."

In an interesting twist, Clinton's husband, former President Bill Clinton, is actually featured in an ISIS recruitment video called "No Respite" which glorifies the caliphate the group established in Iraq and Syria in 2014. It is built on "prophetic methodology," the narrator says, "not a secular state built on man-made laws whose soldiers fight for the interests of...legislators, liars, fornicators, corporations and for the freedoms of Sodomites."

Mr. Clinton's picture appears as the narrator says the word "fornicators." Former President Bush appears during "liars" and President Obama during "legislators."

  • Rebecca Kaplan

    Rebecca Kaplan is a political reporter for CBSNews.com.