The Intelligence panel is expected to hold several additional public hearings as Democrats seek to make the case that Trump abused the power of his office when he pressured Ukraine’s leaders to investigate his political opponents.

“Those open hearings will be an opportunity for the American people to evaluate the witnesses for themselves, to make their own determinations about the credibility of the witnesses, but also to learn first-hand about the facts of the president's misconduct,” Schiff told reporters.

Investigators are also still hearing testimony from witnesses behind closed doors; David Hale, the third highest-ranking official at the State Department, appeared on Wednesday.

Democrats consider Taylor and Yovanovitch among the most compelling witnesses to Trump’s efforts to pressure Ukrainian officials to investigate his political rivals, which is central to the impeachment inquiry.

William Taylor, the top diplomat in Ukraine. | Andrew Harnik/AP Photo

“I think you will see throughout the course of the testimony — not only their testimony but many others — the most important facts are largely not contested,” Schiff said.

Taylor was the first witness to explicitly tie Trump to a quid pro quo with Ukraine, with the White House withholding critical military aid to the country and putting a Trump meeting with Ukrainian President Volodymyr Zelensky on ice until Zelensky committed to pursuing investigations into Trump’s political rivals, including former Vice President Joe Biden.

“It is a rancorous story about whistle-blowers, Mr. Giuliani, side channels, quid pro quos, corruption and interference in elections,” Taylor said, referring to Trump’s personal lawyer Rudy Giuliani.

Yovanovitch was a casualty of that effort. She was recalled from her post in May amid a push by Trump and his allies, including Giuliani, to portray Yovanovitch as disloyal to the president. Yovanovitch testified that she was forced out of her post based on “unfounded and false claims by people with clearly questionable motives.”

Yovanovitch testified that she felt threatened by Trump, who disparaged her during his July 25 phone call with Zelensky. During that conversation, Trump pressured Zelensky to investigate Biden and his son Hunter, in addition to a debunked conspiracy theory about Ukraine’s role in the 2016 presidential election.

Taylor is likely to be asked to discuss his decision to succeed Yovanovitch after her ouster and his deep concerns over what he called a “snake pit” in both Washington and Kyiv.

“Can anyone hope to succeed with the Giuliani-Biden issue swirling for the next 18 months?” Taylor wrote in a text message to Kurt Volker, who served as the top U.S. envoy for Ukraine negotiations. House impeachment investigators released the communications on Tuesday alongside the transcripts of Volker’s testimony.

Investigators released the transcript of Taylor's closed-door testimony later Wednesday.

Under a set of procedures adopted by the full House last week, Republicans can suggest witnesses and subpoenas, though Schiff and the committee's Democratic majority would ultimately have the final say.

Trump and his attorneys are expected to have a role in the process once it moves to the Judiciary Committee, where articles of impeachment will be introduced and amended.

Republicans have criticized the process as giving no due process to the president. Democrats maintain they have adopted the same procedures that were used during the impeachment inquiries of Richard Nixon and Bill Clinton.

Caitlin Oprysko contributed to this report.