GOP leaders on the House panel are eager to wrap up the investigation soon, with influential Republicans saying the exhaustive review has dug through thousands of documents and interviewed virtually every major witness and has found scant evidence of collusion between the Trump campaign and Russian operatives to meddle in the 2016 elections.
But Democrats on the committee say there have been several areas that have not been fully investigated, including financial records from the Trump Organization and key officials in President Donald Trump's orbit, and that they are seriously weighing issuing their own report detailing what they view as the unexplored parts of the inquiry.
Rep. Jim Himes of Connecticut, a senior Democrat on the panel, said Tuesday that the committee does not yet fully understand the full extent of the efforts to give Russian dirt to the President's eldest son, Donald Trump Jr., and George Papadopoulos, the Trump campaign foreign policy adviser.
"I think a lot of work remains to be done on who exactly knew what about Don Jr.'s efforts to get dirt and George Papadopoulos' effort to get dirt on the Clinton campaign," Himes told CNN. "Did those efforts stop with those individuals or was it part of the larger effort within the campaign? I don't think we know the answer to that yet."
Trump Jr., who testified before the House panel in December as well as two Senate committees, has said that he was not given dirt on Hillary Clinton during a June 2016 Trump Tower meeting with a Russian lawyer, as the meeting was focused on US sanctions on Russia.
Rep. Adam Schiff of California and other Democrats have accused House Republicans of trying to swiftly end the House Intelligence Committee investigation as a precursor to ending special counsel Robert Mueller's investigation, which is also looking at ties between Russian officials and Trump's team. But Republicans have rejected that attack, saying Democrats appear intent on pursuing an investigation without end.
"This idea this could go on into perpetuity is just nonsense," Rep. Tom Rooney of Florida, a senior Republican on the panel, told CNN last month. "You can interview anybody that's ever met a Russian in the government, and it's not going to help you get any closer to what the four parameters were, what our job is, what the report is supposed to look like, and to put it out there for the American people to consume."
The growing partisan gap over the House investigation makes it increasingly likely that after investigators spent much of 2017 examining connections between the Trump campaign and Russia, the public may lack a definitive assessment about what occurred in 2016.
And increasingly, Democrats are calling on House Speaker Paul Ryan to intervene, arguing he needs to help an investigation that they say is being undercut by the panel's chairman, Rep. Devin Nunes of California.
"Who can do the most to make sure that this investigation moves forward appropriately? It's the speaker of the House," Rep. Mike Quigley of Illinois, a member of the House panel, told CNN on Tuesday. "He is facilitating the chairman of the Intelligence Committee's desire to take this investigation to a different place and to hinder the Russia investigation."
Ryan spokeswoman AshLee Strong said in a statement: "The investigation will conclude when the committee has reached a conclusion. It's clear by the endless political posturing by some House Democrats that they would like to see this investigation go on forever. Whether it concludes next month, next year, or in three years, they'll say it's too soon."
There are still two other Russia investigations occurring in the Senate, and those appear likely to last longer than the House inquiry, though several Republicans on the Senate Intelligence Committee say the investigation could be reaching its final stages after more than 100 interviews.
Leaders of the House panel still hold out hope that they can release one bipartisan report on the committee's months-long investigation into Russian meddling.
"Hopefully we're working on the same set of facts," said Rep. Mike Conaway, the Texas Republican who is running the probe, adding that the panel was starting to draft its report. "But everybody gets to look at the glass and decide if it's half empty or half full."
But members on both sides of the committee are preparing for the reality that their conclusions about the probe will be simply too far apart for a single report.
Conaway said he wants to make as much of the committee's transcripts public as possible so that the people can draw their own conclusions. He argued that the collusion "narrative" seemed to disappear once the public got a definitive sense of what the committee was discussing behind closed doors, pointing to the panel's release of a transcript of a hearing with Carter Page, a Trump campaign foreign policy adviser.
"We'll put our conclusions in there, but as you saw with Carter Page, there was a narrative that started that disappeared altogether once the public saw what he really said at the interview," Conaway said.
In his House interview
, Page said members of the Trump campaign were aware of his July 2016 trip to Russia, and he disclosed interactions with more Russian government officials beyond what had previously been publicly known.
Schiff, the top Democrat on the panel, has increasingly accused the GOP of seeking to shut down the inquiry by cutting off areas to investigate. Schiff has accused the GOP of blocking subpoenas, including to Deutsche Bank, to look into any business ties between the Trump Organization and Russia. And he has said that a number of witnesses have been rushed through the panel before members were ready to query them, calling for major figures close to Trump to return for another round of questioning.
"It's no way of conducting an investigation, not if you're serious about getting the truth," Schiff said late last month. "It's a way to conduct an investigation if you want to give the appearance of legitimacy or you want to bring things to an end. But it's not designed to get at the truth."
Looming over the investigation is House Intelligence Chairman Nunes, who stepped aside from the Russia investigation last spring amid a House Ethics Committee investigation into his handling of classified information. He was cleared by the panel in December.
Even while he stepped aside publicly, Nunes was involved with the Russia probe from the sidelines throughout the year. He retained subpoena power as the chairman and was able to sign off on or block the committee's subpoena and interview requests.
Nunes, who was on Trump's transition team, has insisted that he never stepped aside from the Russia investigation and was always in control, although Conaway said last month that his role leading the probe did not change after Nunes was cleared by the ethics panel.
And while Conaway has said that Nunes issued every request he asked for, the California Republican's presence has rankled Democrats, who have accused Nunes of trying to undermine the committee's probe.
Nunes' fight with the FBI and Justice Department over documents and interviews connected with the opposition research dossier on Trump and Russia -- he's threatened to hold top officials in contempt of Congress -- have only amplified those tensions in recent weeks, particularly as Republicans and the President have ramped up their attacks on the Justice Department and Mueller.
"It's not a secret that we have an investigation into DOJ," Nunes told CNN last month.
But Democrats accuse Nunes of trying to undercut the probe, and they believe that Ryan is helping him do so.
"The responsibility to conduct a thorough investigation, or to prevent one, ultimately falls on @SpeakerRyan," Schiff tweeted last month. "I'm concerned he's heeding the calls of Bannon and @POTUS to 'DO SOMETHING' by closing down the Russia investigation & opening up another investigation of Hilary Clinton."