“Certainly I’ve never heard of or seen it being this bad,” Mr. Rogers said.
In recent days, the Republican-controlled committee has treated the public to a confusing round-the-clock spectacle over dueling staff-drafted memos that pitted Republicans’ damning characterizations of classified documents against Democrats’ benign ones.
It started last week when the committee Republicans bypassed standard procedures and invoked an obscure rule to declassify and publicize a memorandum accusing top federal law enforcement officials of abusing their powers to win court approval of a secret wiretap order on a former Trump campaign official. No hearings were held, no administration officials were summoned to explain themselves, no bipartisan consultation of possible consequences took place beforehand.
Panel Republicans, backed by President Trump, put out their memo despite a rare statement from the F.B.I. itself, warning that it had “grave concerns about material omissions” that made the document misleading.
Furious Democrats accused the committee’s chairman, Representative Devin Nunes of California, of using the committee’s coveted access to classified information for the nakedly political purpose of bolstering Mr. Trump in the face of a criminal investigation. They raced to prepare their own memo, based on the same underlying material, that sought to rebut the Republican claims, and then reluctantly pushed to release it publicly, too. That document is now under review by Mr. Trump, who will decide whether to make it public.
Even some Republicans were distressed by the tactics of Mr. Nunes and his allies and the tit-for-tat cycle they unleashed. Even if the Republican memo raised legitimate points, Mr. Rogers said, “it’s not an investigation if one side just puts out a few facts.”
Top Democratic leaders last week called for Speaker Paul D. Ryan to remove Mr. Nunes as chairman. But Mr. Ryan has stood by both Mr. Nunes and the memo, saying that the document raised legitimate questions about how the F.B.I. and Justice Department used the Foreign Intelligence Surveillance Act, known as FISA, to investigate a former Trump campaign adviser, Carter Page. Mr. Nunes did not reply to a request for comment.
Republicans on the panel say they are also upset with Representative Adam B. Schiff of California, its top Democrat. They see him as all too eager to step before television cameras to hint at evidence — known only to those like him with security clearances — of nefarious links between Mr. Trump or his campaign and Russian operatives.
“I don’t trust Schiff anymore. I just don’t,” said Representative Tom Rooney of Florida. “I don’t know that I can talk to him privately about something that won’t end up on Rachel Maddow,” he added, referring to the liberal host of an MSNBC program.
Nothing better illustrates those suspicions than Mr. Nunes’s decision to erect a partition between the Republican and Democratic staff members.
Mr. Schiff said he had no choice but to speak out when he saw the committee failing to pursue leads that could illuminate whether the Trump campaign conspired with the Russians. “If you remain silent, then the investigation becomes a whitewash,” he said.
For now, that inquiry is at a standstill. T he last witness interview took place in mid-January. A subpoena was issued to force Stephen K. Bannon, the former White House strategist, to testify, but Democrats say Republicans have so far chosen not to enforce it.
A transcript of a recent committee meeting reads like a tortured divorce hearing. In late January, Representative Mike Quigley, Democrat of Illinois, asked Mr. Nunes whether he had worked with the White House in preparing the Republican memo, which Mr. Trump later said vindicated him in the whole Russia inquiry.
“As far as I know, no,” Mr. Nunes responded. When Mr. Quigley pressed further, Mr. Nunes shut him down: “The chair is not going to entertain a question by another member.”
The Senate Intelligence Committee has been a study in contrasts. Aside from a handful of public hearings, the committee has conducted its Russia investigation behind closed doors. By and large, its proceedings have stayed there, despite more than 120 witness interviews with members of the Trump campaign, the White House and intelligence community.
At least in public, the committee’s top Republican, Richard M. Burr of North Carolina, and Democrat, Mark Warner of Virginia, have projected a unified front. While the House panel was churning out competing memos over whether the F.B.I. abused the FISA process, the Senate committee staff members were working together on a joint interim report on how to protect election security in November’s midterms.
The legislation that set up both committees in the mid-1970s envisioned a compact: The nation’s intelligence and law enforcement agencies would share highly sensitive secrets with a select group of lawmakers and senior aides with the understanding that the information would be carefully protected. But the authors of the legislation deliberately included a check on the agencies. The committees could vote to release classified information if they deemed it to serve the public interest, as long as the president did not object.
There is a long waiting list for a spot on the House panel, and a tradition to uphold. Legislators and staff members like to repeat the mantra that they check their politics with their cellphones when they enter the secure rooms to review classified information or interview witnesses.
Those now seem like empty boasts. “Everything now, you feel, is just being done to set up for the next political posturing,” Mr. Rooney said.
Representative Jim Himes, Democrat of Connecticut, agreed. “To do oversight, we need to be functional, and right now we are not functional,” he said.
K. Michael Conaway, a Republican from Texas who has helped run the day-to-day Russia investigation, said he was hopeful that tensions would eventually fade. But at the moment, he acknowledged, it seems like “the worst thing ever.”
Some senior career officials at the government’s intelligence agencies, endowed with around $80 billion a year in funding, warn that the next time the House committee seeks classified materials or briefings, there will be more reluctance than usual to cooperate.
When lawmakers suddenly declassify secret information over the objections of those who provided it, the reaction of agency officials, whistle-blowers and even intelligence officials in allied countries is predictable, said Steven Aftergood, the director of the Project on Government Secrecy at the Federation of American Scientists: “Wait a minute. We had better think twice about what we share.”