WASHINGTON (CN) – The House of Representatives brought President Donald Trump one step closer to facing impeachment Thursday as lawmakers voted 232-196, split on party lines, in favor of a resolution that outlines precisely how the impeachment inquiry will unfold in the coming weeks and months.

Just the last 37 days have seen a litany of depositions take place behind closed doors at a rapid clip as lawmakers on the House Intelligence, Foreign Affairs and Oversight Committees interviewed one Trump administration official after the other about the president’s July 25 phone call with Ukraine President Volodomyr Zelensky.

No transcript of the call has been made public and to date the White House has only released a summary. But testimony from officials with firsthand knowledge of the call, like Lieutenant Colonel Alex Vindman, did little to help the president’s defense that the call with Zelensky was “perfect” and never featured a threat to withhold military aid lest Ukraine launch a probe into former Vice President Joe Biden, Biden’s son Hunter and Burisma Holdings, the Ukrainian energy firm where Hunter formerly served as a board member.

Vindman, the top Ukraine expert on the National Security Council, told lawmakers the ellipses in the summary of the transcript released by the White House specifically left out mentions of the Bidens and Burisma. That testimony also traced the cover-up all the way up to one of the White House’s own lawyers, John Eisenberg, according to reports published late Wednesday, citing sources familiar with the confidential hearing.

Eisenberg is said to have gotten wind about the lieutenant colonel’s concerns about the call, then taken the transcript and housed it on a highly classified server where fewer people could access it. The lawyer is expected to be called for testimony on Nov. 4. but it is unclear if he will cooperate.

Vindman’s testimony only further whet the appetite for Thursday’s resolution among Democrats who say they are eager to outline the rules of the road for the inquiry as it transitions the from a closed setting to an open one. Given the national-security implications of testimony, it is expected that some hearings will still be held behind closed doors.

But for Democrats who will have a hard fight to move articles of impeachment from the House and to the Senate, transparency and accountability now are key.

“I support this resolution because it’s indefensible that any official demand of an ally, and one depending on our support in an existential struggle with Russia, to investigate his political adversaries,” House Judiciary Committee Chairman Jerry Nadler said during debate on the House floor Thursday. “No person, Republican or Democrat should be permitted to jeopardize American’s security and reputation for self-serving purposes.”