At the time, Giuliani’s associates often found themselves blindsided. “We wondered where he was getting all this stuff,” a person who worked with Giuliani for a long time told POLITICO.

The intensity of Solomon’s reporting back then has stuck in the minds of Giuliani’s old allies — making his recent heel-turn as a fellow traveler with Giuliani in the current Ukraine scandal “very odd,” said this person. It was Solomon who, as a reporter and opinion journalist at The Hill, wrote many of the stories that promoted Giuliani’s narrative of a Joe and Hunter Biden running amok in Kyiv in league with the previous Ukrainian government.

It’s a narrative that became an obsession of the president of the United States, Donald Trump, landing him in a congressional probe that has led to his impeachment by the House of Representatives and placed his re-election in doubt.

Those stories are now under review by The Hill, according to executive editor Bob Cusack, amid questions about their accuracy and an uproar among the publication’s reporting staff. As for Solomon, he stands by his articles, but has left The Hill to start his own media company and continues as a contributor to Fox News.

Solomon’s 2007-vintage reporting has not undergone any similar scrutiny — nor has it been disputed — but Giuliani associates sometimes found it maddeningly granular. One story, for instance, hit the former mayor and his firm for hiring Pasquale D’Amuro, a former top FBI official, focusing on the fact that D’Amuro had once asked a subordinate to retrieve building remains from the post-9/11 wreckage of the Twin Towers as relics.

A spokesperson for Giuliani, Christianné Allen, slammed Solomon’s old Washington Post stories that were critical of her current boss. “Mayor Giuliani had very little involvement in Solomon’s stories in 2007 and 2008 and has in the past stated they were poorly sourced, exceedingly exaggerated, and had little impact on his campaign,” she said. Solomon didn’t respond to an email asking him to respond to that statement.

Peter Baker, the current chief White House correspondent for the New York Times, worked on at least one of those stories with Solomon when they were both at the Post. “Everything I worked on with him that we published was good reporting, and accurate and fair and all that good stuff,” he told POLITICO.

Those who interacted with Solomon during the 2008 Republican primary considered him “relentless,” “annoying” and a “dog with a bone” – a typical set of virtues for an investigative reporter.

“He was interested in telling a side that maybe other reporters weren’t,” said a former senior RNC operative in the 2000s who dealt with Solomon.

“He wasn’t afraid to call you out on your BS if even the slightest detail was off,” recalled a friend of Giuliani’s who worked on the campaign.

One person who worked with Solomon at the Post said they liked Solomon, but found him hard to work with and said that his proposed stories often didn’t pan out. “You just had to say, ‘John, what the fuck? You don’t have this thing.’ And he would say ‘OK, alright, I’ll do something else.’”

Twelve years later and in the swirl of Trump’s impeachment, Giuliani and Solomon seem to have become almost co-dependent as both men seek to investigate Hunter Biden’s stint on the board of Burisma, a Ukrainian energy company facing corruption allegations in Kyiv. The Bidens have denied any wrongdoing, and other reporters have been unable to substantiate the allegations.

As Giuliani himself claimed to Glenn Beck in November, he and Solomon had joined forces to turn the Ukraine narrative into a nationwide event. “I said to John, I think you should take the lead and we should put this all in the newspapers because if I go to the Justice Department now, they’re going to say Trump is forcing the Justice Department to do it. Let’s put the darn thing out, and let’s see if any of these crooked media people will follow up on a proven case of bribery.” Solomon’s own lawyers are Victoria Toensing and Joe diGenova, who also represent Ukrainian oligarch Dmitry Firtash, who has been fighting his extradition to the United States.

In a different interview, Giuliani boasted that he sling-shot Solomon’s Ukraine reporting into the public eye. “I said, ‘John, let’s make this as prominent as possible,’” Giuliani recently told The New Yorker. “‘I’ll go on TV. You go on TV. You do columns.’” He then included Solomon’s columns on Ukraine in a dossier to Secretary of State Mike Pompeo, who handed them over to the department’s inspector general.

Solomon himself contributed to the joint effort by sharing unpublished drafts of his columns with Toensing, diGenova, and Ukrainian-American businessman and Giuliani associate Lev Parnas, according to the New York Times. Several witnesses, in sworn congressional testimony during the House’s impeachment inquiry, said that critical reporting on former U.S. ambassador to Ukraine Marie Yovanovitch — including Solomon’s — was inaccurate and amounted to an effort to smear a well-regarded, veteran diplomat.

The irony of how Solomon and Giuliani’s relationship has changed appears to elude both men.

Giuliani, in an email, said he didn’t remember Solomon from the 2008 campaign and his stories “had little real impact on my campaign, which failed for other reasons.”

And Solomon, for his part, said in a phone interview that the narrative that he worked with Giuliani on his Ukraine stories was wrong and that he never used any Ukraine information from Giuliani until a single column in September about how some State Department officials had encouraged and helped connect Giuliani to an adviser for Ukrainian President Volodymyr Zelensky.