In 2017, Chalupa told POLITICO reporters that officials at the Ukrainian Embassy were "helpful" to her effort to raise the alarm about Manafort. "If I asked a question, they would provide guidance, or if there was someone I needed to follow up with," she said.

But she also downplayed the idea that the embassy was conspiring to interfere in American politics. "There were no documents given, nothing like that," she said. "They were being very protective and not speaking to the press as much as they should have. I think they were being careful because their situation was that they had to be very, very careful because they could not pick sides. It’s a political issue, and they didn’t want to get involved politically because they couldn’t.”

Andrii Telizhenko, a 29-year-old former political officer in the Ukrainian Embassy who says he was tasked with helping Chalupa dig up dirt on Manafort in 2016, has gone further, claiming there was direct coordination between the DNC and the Ukrainian government.

Telizhenko met with Trump’s personal lawyer Rudy Giuliani earlier this year to discuss “Ukrainian collusion” with Democrats during the election, and Giuliani told Fox News last month that “Telizhenko has direct evidence” of the coordination.

Telizhenko's claims have not been proved, however. The DNC has said Chalupa conducted the Manafort research on her own, and the so-called black ledger outlining off-the-books payments Manafort received from Ukraine’s pro-Russia Party of Regions—and that ultimately forced Manafort’s resignation from the Trump campaign—was released by an independent Ukrainian government agency and publicized by a Ukrainian member of Parliament.

Republicans highlighted the Chalupa episode as part of an 18-page impeachment defense memo they expect to drive their effort to undermine Democrats' case that Trump abused his power in his dealings with Ukraine.

But Chalupa says her part of the story has been magnified and distorted to the point that it's little more than a smear campaign initially disseminated by Russia.

“The whole story originated with the Kremlin,” Chalupa said in an interview on Monday, pointing to an initial December 2016 statement from Russia’s spokeswoman accusing the Ukrainian government of trying to sabotage Trump’s campaign by exposing that Manafort hid millions in payment for his work pushing Kremlin-backed candidates in Ukraine.

The narrative that the government of Ukraine meddled in 2016 using Chalupa as an intermediary has made a comeback among Trump defenders as they beat back a mountain of emerging evidence that Trump used his leverage over Ukraine to pressure the country's leaders to investigate his political rivals, including former Vice President Joe Biden and the 2016 presidential campaign of former Secretary of State Hillary Clinton.

Democrats have laid out a case that Trump, using Giuliani as an intermediary, deployed the might of the State Department to pressure Ukraine's new president, Volodymyr Zelensky, to launch the president’s favored investigations. The case includes allegations that Trump withheld a White House meeting and nearly $400 million in military aid to bend Ukraine to his will.

Despite the widely understood difference in the scale of activities by Russian and Ukrainian officials in 2016, Trump allies have claimed that Chalupa's work, which preceded Manafort's resignation from the Trump campaign and his eventual conviction for multiple financial crimes related to his activities in Kyiv, is evidence that foreign election interference plagued both campaigns in similar ways.

Fiona Hill, Trump's former Russia adviser on the National Security Council, said she and other senior national security officials spent years trying to disabuse Trump of this notion. In testimony before House impeachment investigators last month, she blasted GOP lawmakers, saying their questions about Ukraine's role in 2016 echoed the false stories that emerged that year and were diversions from the threat Russia poses.

"The Ukrainian government did not interfere in the U.S. election. The Ukrainian government did not do that," Hill said under questioning from Rep. Lee Zeldin (R-N.Y.). "The Ukrainian Special Services also did not interfere in our election," she added, alluding to the involvement of Russia’s intelligence agencies in the 2016 interference campaign.

But Republicans' decision to call Chalupa suggests that they intend to highlight the Ukraine-interference narrative despite Hill's warning.

Chalupa, for her part, emphasized she'll relish the opportunity to push back on their claims if called.

“It’s clear Republicans are gaslighting the public by putting me on their list of witnesses,” she said. “It’s a bluff meant to smear and distract from Donald Trump’s impeachable offenses. I’m the last person Republicans want to testify publicly. My testimony would be especially damaging to Donald Trump, Paul Manafort and Vladimir Putin. The GOP knows this.”

Chalupa, who has never been to Ukraine, began investigating Manafort and his ties to Russia in 2014 after a meeting she and other Ukrainian-Americans attended at the White House to discuss Ukrainian President Viktor Yanukovych and the popular protests that had ousted him. She attended the meeting, held with National Security Council officials, as part of her unpaid work “building stronger bridges of alliance” between the White House and the Ukrainian community, she said.

“I began sounding the alarm bells about Manafort in 2014,” Chalupa said. Yanukovych fled to Russia, which invaded Crimea shortly thereafter. Ukraine and Russia have been at war ever since.

“The shocking part is that this entire town wasn’t sounding alarm bells,” Chalupa said. “Manafort and I have been going head-to-head since 2014. All the Ukrainian-Americans knew how dangerous he was.”

In April 2017, prosecutors in Kyiv reportedly began investigating Manafort’s role in the shooting of anti-government protesters in February 2014 when he was still Yanukovych’s top adviser. The renewed interest stemmed from a cellphone hack of one of Manafort’s daughtes, in which she’d texted her sister about their dad. “Don't fool yourself. That money we have is blood money,” read one text. “You know he has killed people in Ukraine? Knowingly,” read another. Manafort confirmed at the time that some of the messages were authentic.

The disgraced former operative is now serving a seven-year prison sentence on tax and bank fraud charges. But in recent congressional hearings he’s been treated as collateral damage in the campaign to undermine Trump’s candidacy in 2016.

In the deposition of William Taylor, the top U.S. diplomat in Ukraine, lead GOP counsel Steve Castor homed in on a POLITICO report that said one Ukrainian member of Parliament had leaked a so-called black ledger of Manafort’s finances because he wanted to undermine Trump. The ledger appeared to show $12.7 million in cash payments that were earmarked for Manafort by Yanukovych’s pro-Russia Party of Regions.

Castor also asked Taylor whether he knew of “the allegation that a DNC-connected consultant was communicating with the Ukrainian Embassy here in D.C.” — likely a reference to Chalupa, who was working as a part-time consultant focused on mobilizing ethnic communities at the DNC in 2016.

In March of that year, Chalupa alerted the Ukrainian ambassador, Valeriy Chaly, to her concerns about Manafort’s ties to Russia and work for the Trump campaign, she said.

Castor brought up Chalupa by name while questioning the former U.S. ambassador to Ukraine, Marie Yovanovitch. “Do you know about any efforts that she undertook to work with the Ukrainian Embassy to further negative information about the now-President Trump?”

Yovanovitch said she’d only heard what she read in the media.

When Castor asked Hill about efforts to push out negative information about Manafort in 2016, she characterized it as a distraction.

“There are Ukrainians pushing out information about Masha Yovanovitch which is untrue,” Hill shot back, referring to two Giuliani associates who waged a smear campaign against Yovanovitch that ultimately led to her removal. “Why don't you ask about that as well? Is Masha Yovanovitch any less of an American than Mr. Manafort? She has not been accused of any corruption.”

It’s not only GOP House members who are interested in Chalupa, however. The right-wing activist group Judicial Watch recently obtained visitor logs placing Chalupa at the White House several times in 2015, where she attended meetings related to countering disinformation with other Ukrainian-Americans and sometimes worked with the White House’s Office of Public Liaison to organize ethnic engagement events, she said.

A photo of her at one of those meetings—standing next to a man that conservative news outlets have identified as the official who blew the whistle on Trump’s interactions with Zelensky—has again placed Chalupa at the center of controversy.

She mused in an interview about how Republicans would be reacting now if she’d actually taken a job in Ukraine that required her to shuttle back and forth from Kyiv to D.C. during the 2016 campaign. A position as an “embedded consultant” in the Ministry of Foreign Affairs was offered to her the day WikiLeaks began publishing stolen DNC documents in July 2016, according to an email reviewed by Politico.

“I never responded to it,” Chalupa said. “Felt it was a trap.”

It's unclear whether House Intelligence Chairman Adam Schiff, the leader of the impeachment inquiry, will allow Republicans to call Chalupa. He and the panel's Democrats control which witnesses testify in public hearings, and Schiff has indicated he won't permit Republicans to attempt to divert the focus from allegations that Trump abused his power.

“As an expert on political hybrid warfare, including from first-hand experience being targeted by the Kremlin for the past four years, I’m confident there’s a lot I can contribute to the hearings,” Chalupa said. “For now, it seems the focus is exactly where it needs to be — on Donald Trump and his accomplices trying to extort Ukraine, a U.S. ally defending itself from Russia’s ongoing military and hybrid warfare.”

