A name long associated with the Clinton machine has surfaced as a behind-the-scenes figure in the Trump-Russia collusion story, prompting some to speculate that the investigation began at least partly as a dirty tricks operation.

Sidney Blumenthal, a Clinton loyalist from the days of Bill Clinton’s presidency up through Hillary Clinton’s presidential campaigns, was identified by Rep. Trey Gowdy, R-S.C., as a source of anti-Trump information passed to the FBI through the State Department. The information is believed to have played a role in the FBI’s launching of the collusion probe that is now in the hands of Special Counsel Robert Mueller.

Blumenthal has long been known as an attack dog for the Clintons, so ferocious a defender that he earned the nickname “Sid Vicious.” As Dick Morris, former adviser to the Clintons (although he has since become a critic) puts it, “If [Bill Clinton] is caught shoplifting for the tenth time, Hillary would have Sidney blame the store’s cameras.”

Blumenthal started out as a journalist, writing for the “New Republic,” the “Washington Post” and “The New Yorker,” before joining the Clinton White House in 1997. He was soon embroiled in the Monica Lewinsky scandal, called to testify before a grand jury by independent counsel Ken Starr, though he refused to answer questions about confidential White House conversations on the matter.

At the time, journalist Christopher Hitchens submitted an affidavit that Blumenthal had described Monica Lewinsky as a stalker, though Blumenthal denied this.

When Bill Clinton left office, Blumenthal returned to journalism and gained a reputation as being pro-Clinton—so pro-Clinton, in fact, that some fellow journalists felt it was unseemly.

He worked as an adviser in the 2008 Hillary Clinton presidential campaign, and allegedly spread anti-Barack Obama stories. Journalist James Asher stated Blumenthal told him to investigate if President Obama was born in Kenya, though Blumenthal denies this.

Whatever happened, the Obama administration was apparently so angry at Blumenthal that Chief of Staff Rahm Emanuel blocked him from working on Hillary Clinton’s staff when she was named secretary of state, claiming his presence was too divisive, even poisonous.

Instead, Blumenthal went to work at the Clinton Foundation, and kept in touch with Hillary. He sent her policy advice, including a reported 25 emails about Libya in 2011 and 2012. A few years later, Republicans on the Benghazi committee asked Hillary about the Blumenthal connection. In a leaked email, John Podesta, Clinton’s campaign boss, believed Blumenthal to be “lost in his own web of conspiracies.”

Around this time, Hillary defended her connection with Blumenthal, stating “I’m going to keep talking to my old friends, whoever they are….He sent me unsolicited emails, which I passed on in some instances, and that’s just part of the give-and-take.”

And now it appears Blumenthal was likely there, behind the scenes, helping to spread information tying the Trump campaign to Russia. It would appear to fit his MO—as Dick Morris claims, “Sidney Blumenthal is Hillary’s go-to guy for off-the-shelf dirty ops.”

The question now is will the Russia story continue to bedevil Trump, or will it be turned around on his accusers?

Additional reporting by Kristine Kotta