If Congress is to get to the bottom of President Trump’s efforts to get the Ukrainian government to investigate former Vice President Joe Biden, Rudolph W. Giuliani is an obvious choice for the witness list.

But Democrats are split as to whether he would do more harm than good to their nascent impeachment inquiry and some expressed concern that hauling a loose cannon like Giuliani in front of a committee would risk a replay of the circus-like atmosphere created by Trump loyalist and former campaign manager Corey Lewandowski—a scene few Democrats are eager to recreate.

Still, aside from acting Director of National Intelligence Joseph Maguire and the anonymous whistleblower who first raised Trump’s phone call with Ukrainian President Volodymyr Zelensky, Giuliani would perhaps be the next most important witness in the Ukraine-focused probe that House Democrats are promising to conduct.

For months, the president’s personal attorney has pushed the new president of Ukraine to open a probe into the business dealings of Biden’s son Hunter in the country, as well as Biden’s own role in them, right as the two-term veep launched his own campaign to challenge Trump in 2020.

And in the wake of new details about a complaint from an anonymous whistleblower regarding Trump’s contact with Ukraine, Giuliani has embarked on a scorched-earth media tour, getting into shouting matches with cable TV news hosts as he insists they did nothing wrong—in the process making startling admissions that have fueled scrutiny on the matter.

There’s “no question” that House Democrats have to bring Giuliani in for testimony, said Rep. Jackie Speier (D-CA), a member of the House Intelligence Committee. "I think it would be revealing to the public.”

Late on Wednesday, Democrats on the Intelligence Committee learned more about the whistleblower’s complaint, viewing a version of it in a closed setting, and came out saying that several figures, including Giuliani, had questions to answer.

“I think at some point,” said Rep. Jim Himes (D-CT), an Intelligence Committee member, “we’re going to want to talk to Rudy Giuliani.”

Not everyone is on board with this plan. Democrats are already well aware of the challenge presented by a loose cannon Trumpworld figure, and they still feel burned by Lewandowski. The former Trump campaign manager’s combative five-hour session before the House Judiciary Committee on Sept. 17 amounted to a massive middle finger to Democrats, who afterward privately panned the hearing as a disaster.

Given Giuliani’s track record of theatrics and his fierce loyalty to the president, some Democrats worry that his testimony wouldn’t contribute to legitimate fact-finding but rather turn Democrats’ sober-minded mission into a complete circus—as well as slow down an impeachment proceeding that nearly all Democrats believe needs to be completed with the utmost speed.

“ I don’t know if we need to complicate this too much with a madman like Rudy Giuliani in Congress. ” — Rep. Eric Swalwell

Rep. Eric Swalwell (D-CA), a member of the Intelligence and Judiciary Committees, predicted a Giuliani testimony would be a Lewandowski-like spectacle and simply amplify the partisan takes he brings to cable news nightly.

“I don’t know if we need to complicate this too much with a madman like Rudy Giuliani in Congress,” said Swalwell. “Why waste your time?”

Swalwell also argued that Giuliani’s testimony is largely not needed to further prove wrongdoing: “The president admitted to this,” he said, referencing the memorandum that was released Wednesday morning describing Trump’s call with Zelensky, in which Biden was discussed and the president asked his counterpart for a “favor.”

Giuliani himself has indicated that Democrats face a tough slog if they want him before the Hill’s klieg lights. Asked on Monday by The Daily Beast if he’d agree to an interview with Congress, Giuliani replied: “No, not [with] the corrupt ones like Schiff and Nadler,” in reference to the chairmen of the Intelligence and Judiciary Committees, respectively.

A spokesperson for Schiff, whose Intelligence Committee is leading the investigation into the whistleblower’s allegations, declined to comment. It is unlikely that Judiciary would request Giuliani’s appearance and a spokesperson did not say if they would. A spokesperson for the House Foreign Affairs Committee—which has been probing Giuliani’s Ukraine activity and has requested documents from him—did not say either if they would call him to testify.

Giuliani also cited attorney-client privilege between himself and President Trump as a reason for him not to testify, indicating that Democrats would likely face a court fight to compel his appearance. Such a move would greatly slow down the quick-strike impeachment proceedings that Democrats have outlined—just as similar stonewalling slowed down their investigations into the obstruction of justice outlined in Robert Mueller’s report.

“I think the president depends on these drawn-out battles where he can use his friends in the media and his friends in Congress to spin the message and try to confuse people and distract from the real issue,” said Rep. Justin Amash (I-MI), whose support for impeaching Trump prompted his departure from the GOP.

Still, the belief that Giuliani is a key figure in all this—“right in the center” of the story, said one member—might win out among Democrats.

“I mean, it seems that he's had more than one conversation with persons from Ukraine, about digging up dirt on the president's political opponent,” said Rep. Val Demings (D-FL), an Intelligence Committee member. “So there is no doubt, based on what the White House released itself, that the president's personal attorney is playing a major role in this mess that we currently have.”