The Bashar al-Assad regime in Syria has had a quiet but well-funded lobbying effort in Washington, D.C., since well before he began murdering his own people. But that influence campaign’s clearest triumph came only this month, when it succeeded in bringing Rep. Tulsi Gabbard, D-Hawaii, to Damascus and having her parrot Assad’s propaganda on her return.

Gabbard was not the first U.S. elected official to meet Assad. In the early years of Assad’s presidency, several senior U.S. lawmakers publicly traveled to see the young English-speaking optometrist-turned-ruler, in the hope that he might be a reformer, break with Iran and even make peace with Israel.

Then-House Speaker Nancy Pelosi, D-Calif., visited Assad in 2007. Then-Sen. John Kerry, D-Mass., led a delegation in 2009.

After the killing began in 2011, however, Assad’s friends in Washington largely went underground and a covert influence and intimidation campaign blossomed. The FBI began investigating Syrian ambassador Imad Moustapha, due to evidence he was keeping tabs on Syrian Americans who showed disloyalty so the Syrian government could threaten their families back home. Moustapha departed for Beijing in 2012, but he left in place a network of friends, Syrian Americans who nurtured close ties to the regime and worked on Assad’s behalf.

One Syrian-American who was close to Moustapha and would often visit his Washington residence was Cleveland businessman Bassam Khawam, according to three Syrian Americans who saw them together but do not wish to be identified for fear of retribution. Five years later, Moustapha is nowhere to be seen, but Khawam is still active. He organized and joined the trip to Damascus for Gabbard and arranged a meeting with Assad.

“This guy has been lobbying on behalf of Bashar Assad in the U.S. even before there was a revolution, and we are deeply troubled he would try to help a war criminal build relationships with sitting members of Congress,” said Mohammed Alaa Ghanem, director of government relations for the Syrian American Council, a nongovernmental organization that works with the Syrian opposition.

Former congressman Dennis Kucinich, D-Ohio, also joined the trip, which is no mere coincidence. Khawam arranged for Kucinich to meet Assad multiple times, most recently in 2013. He donated to Kucinich’s campaigns and in related Federal Election Commission filings listed himself as a self-employed physician.

In other FEC filings, Khawam has listed himself as executive director of ACCESS Ohio, which presents itself as a branch of the Michigan-based Arab Community Center for Economic and Social Services. Gabbard says that ACCESS Ohio paid for her trip. The problem is, ACCESS Ohio hasn’t existed for several years.

“I can assure you 1/8Khawam3/8 has never been an employee of the organization and he is not at all affiliated with ACCESS,” Rana Taylor, director of communications for the entire ACCESS organization, told me.

She explained that ACCESS had set up a national network for Arab-American communities and that there had been an Ohio member organization many years ago, but said it was long defunct. “They don’t have any type of structure or governing body,” said Taylor. “They are non- functioning, not active as a member in any way.”

Gabbard, in a press release, called Bassam Khawam and his brother, Elie, who also joined the trip, “longtime peace advocates.” Her office told me she had “no prior knowledge or relationship” with the pair and directed all inquiries to the organization or Kucinich. Messages left for Khawam and Kucinich were not retuned.

The actual source of the funding for the trip is murky, too. But there’s no doubt the Assad regime facilitated it. Not only did the group get an audience with the president, but they also received access to sensitive areas under the protection of government forces. In several arranged meetings, Syrians told Gabbard that Assad is a benevolent ruler fighting terrorists and that the U.S. policy of opposing him is unjust.

Upon her return, Gabbard referenced those Syrians in interviews and op-eds to reinforce her long-held opposition to what she calls the U.S. “regime change” policy in Syria. She also asserted there are no moderate rebels in Syria and that the United States is funding and arming al-Qaida and the Islamic State. Neither is true, but both match the talking points that the Assad regime has been pushing for the entirety of the war.

Principled opposition to U.S. intervention in Syria is one thing. Becoming a tool of a mass murderer’s propaganda and influence campaign is another. Gabbard’s cooperation with the Syrian regime damages her effort to promote herself as a legitimate foreign policy voice.

If Gabbard really didn’t know the men who sponsored her “fact-finding mission” to Syria, she should have. To many, the entire affair proves that Assad’s Washington influence campaign is alive and well and now has a sitting congresswoman for a mouthpiece, whether she realizes it or not.

Josh Rogin wrote this for The Washington Post.