On Monday, March 20th, the House intelligence committee will hold its first open hearing on Russia’s meddling in the 2016 Presidential campaign. Because Republican leaders in the House and Senate have blocked any attempt at forming an independent committee modelled on the bipartisan 9/11 Commission to dig into the Russian cyber attack, the intelligence committee’s investigation may be the only chance Americans have at receiving a comprehensive report on the breadth of the Russian hacking.

The top Democrat on the committee is Adam Schiff, a congressman from Los Angeles who was first elected in 2000. Before the election of Donald Trump, Schiff was known in Washington as a milquetoast moderate. But, appalled by Trump’s muted response to the Russian attack, Schiff has emerged as an unlikely face of Democratic resistance to the new President, using his position on the intelligence committee to pursue an investigation of the Russian influence campaign, its potential links to Trump and his associates, and how America should respond. He’s convinced that the Democrats won’t be the last American victims of the Russians. “One of the things that the intelligence community concluded was that there will be a next time,” he told me on Monday. “They will do this again.”

Despite his understated reputation, Schiff has gained a quiet respect among foreign-policy liberals and reporters for his nuanced views on surveillance, war powers, and press freedoms. He championed reform of the Patriot Act after the revelations by Edward Snowden about the N.S.A.’s bulk collection of metadata. He pushed for a new, more tailored war authorization against Al Qaeda to replace the overly expansive one put in place after 9/11. And he has been outspoken on free-press issues, both in the United States and abroad.

In response to the Russian hacks, Schiff’s preference was to have an outside investigation. The 9/11 Commission, run by Tom Kean, the former Republican governor of New Jersey, and Lee Hamilton, the former top House Democrat on both the intelligence and foreign-affairs committees, was governed by consensus and a strict goal of producing a report that its members, divided between the two parties, could endorse unanimously.

It remains to be seen whether any committee in the hyper-partisan House of Representatives can follow that model. “There’s still a significant question of ultimately whether we’ll be able to complete this investigation the way you should,” Schiff told me. “Certainly people have their skepticism, and the only thing I can say is that I fully believe it’s in the national interest to try. Because the best thing for the country would be for us to reach a common conclusion at the end of the investigation about what took place. And if it ends up being the Democrats issue one report and the Republicans issue another, we won’t have added a lot of value.”

The Republican chairman of the committee is Devin Nunes, who served as an adviser on the Trump transition and has spent the last few weeks awkwardly trying to defend the Administration even as he has struck an agreement with Schiff to conduct a fairly broad investigation. While Nunes is a partisan Republican, he was best known in recent years as an outspoken critic of his congressional colleagues on the right who he believed were damaging the Republican Party with tactics such as government shutdowns. He called them “lemmings with suicide vests.”

In late 2015, Nunes told me that the biggest concern he had was the spread of false information on the right:

"I used to spend ninety per cent of my constituent-response time on people who call, e-mail, or send a letter, such as, 'I really like this bill, H.R. 123,' and they really believe in it because they heard about it through one of the groups that they belong to, but their view was based on actual legislation," Nunes said. “Ten per cent were about ‘Chemtrails from airplanes are poisoning me’ to every other conspiracy theory that’s out there. And that has essentially flipped on its head.” The overwhelming majority of his constituent mail is now about the far-out ideas, and only a small portion is “based on something that is mostly true.” He added, “It’s dramatically changed politics and politicians, and what they’re doing.

Schiff and Nunes had already agreed to the scope of their investigation when, on March 4th, Trump wrote, in an early-morning series of tweets, “Terrible! Just found out that Obama had my 'wires tapped' in Trump Tower just before the victory. Nothing found. This is McCarthyism!” He added, “How low has President Obama gone to tapp my phones during the very sacred election process. This is Nixon/Watergate. Bad (or sick) guy!”

Talking to reporters a few days later, Nunes mounted a defense of Trump’s reckless allegation. “The President is a neophyte to politics,” Nunes said. “He’s been doing this a little over a year. And I think a lot of the things that he says you guys sometimes take literally. Sometimes he doesn’t have twenty-seven lawyers and staff looking at what he does, which is, I think, at times refreshing.” He added, “I don't think we should attack the President for tweeting.”

The White House, struggling to defend Trump’s allegation, deflected requests for proof by calling on Congress to investigate. Schiff gladly accepted the challenge—on Monday, most of the attention will be on Trump and his claim that Obama ordered surveillance against him.

James Comey, the F.B.I. director, is scheduled to testify, and Schiff is almost giddy at the prospect. Schiff is a former prosecutor who, in 1990, after two previous trials, convicted the first F.B.I. agent indicted for espionage, a case that also involved the Russians. Schiff seems ready to cross-examine Comey, who was reportedly furious about Trump’s tweet and wanted the Department of Justice to respond to it. “If the press reports are accurate and Comey wanted the Department of Justice to refute this and they were unwilling, then he’ll have the chance to do it,” Schiff said. “What is the F.B.I.’s response to this accusation that President Trump made against his predecessor when he called him sick and bad because he was illegally wiretapping Donald Trump?” He added, “I think we’ll have the chance in an open hearing to quite definitively put this to rest, and then the President will have to explain why he made this up.”