"Adam Schiff is really coming out as a leader right now," said Karen Skelton, a Democratic political strategist in Sacramento and former political adviser in the Bill Clinton White House.
Schiff is much more visible in characterizing the evidence in the Russia investigation in dark tones than his Democratic counterpart on the Senate Intelligence Committee, Mark Warner of Virginia. That means Schiff will be vulnerable to criticism if the investigation does not deliver.
An eye on Feinstein's Senate seat
Schiff has political ambition and considered running for the U.S. Senate last year before deciding to step aside in favor of Kamala Harris, who won the election. He's expected to be among the contenders for Feinstein's seat if the 83-year-old senator decides not to run for re-election next year.
"I hope Senator Feinstein runs again. I think she's doing a great job. Her experience is more valuable now more than ever," Schiff said.
Schiff, 56, would have a tough campaign in a crowded field if Feinstein opts out and he decides to run. A new Berkeley IGS poll found just 5 percent support for Schiff in such a race, trailing other hypothetical contenders such as Gov. Jerry Brown (23 percent), Los Angeles Mayor Eric Garcetti (8 percent) and Rep. Jackie Speier of Hillsborough (7 percent).
Poll Director Mark DiCamillo said the fact that Schiff registered just 5 percent during a time when he's the most visible figure in the Russia probe "demonstrates again and again, how closely California voters are following the news."
"It's very difficult for a congressperson, a Schiff or anyone else, to suddenly become a well-known household name to the overall California electorate," he said.
An understated style
Schiff's understated style is unusual at a time of chaos in national politics. He pauses to think before he speaks, and when he speaks, it is to make pointed accusations against the president in gentle, disappointed tones.
"He's playing a role that I could see him imagining that someday he might be lucky enough to be in a position to play — to investigate something as important as this," said strategist Skelton. "People of my generation are hearing echoes of Watergate and Adam Schiff is the right place to ask the questions."
'Not the Adam I know'
Schiff has become more partisan, said Rep. Ileana Ros-Lehtinen, a Florida Republican on the Intelligence Committee.
"This new iteration of Adam is not the Adam I know," she said.
Schiff said the investigation is about national and global security, and not about partisan politics.
"This investigation is phenomenally important," Schiff said in an interview. "We're in a real struggle between authoritarianism and autocracy and democracy and representative government. Right now autocracy is on the march."
Relationship with Nunes on the rocks
Schiff's ascendancy on the national stage comes as his Republican counterpart on the House Intelligence Committee, Chairman Devin Nunes, stands accused of bungling the committee's Russia investigation. Nunes, from Tulare, Calif., stepped aside from the investigation amid questions over whether he inappropriately revealed classified information.
Nunes and Schiff until recently worked in unusually close cooperation, a marriage that is now badly on the rocks.
"It's very strained, there's no avoiding it," Schiff said.
Charges of partisanship
Republicans with whom Schiff has worked in the past say the serious, thoughtful lawmaker they valued is turning into more of a partisan figure.
Ros-Lehtinen said she is counting on the Schiff she's known to help the committee's investigation get back on track.
"Now we're a little bit like a Telemundo telenovela, but soon we will get back to regular programming and Adam Schiff has always been an honest broker," she said.
Schiff is facing his own call to step aside from the investigation. Former Republican Rep. Mike Rogers, who was House Intelligence Committee chairman until 2015 and is now a CNN commentator, argues Schiff has gone too far with his public comments about the evidence. Schiff called Rogers' suggestion "not serious."
Championed by Democrats
His Democratic colleagues on the House Intelligence Committee describe the deliberative Schiff as perfectly suited to lead their party in the Russia investigation, where the outmanned Democrats have little power other than pointed public questioning of the president.
"Among the 194 Democrats in the U.S. House I cannot imagine a single person who I would rather have as ranking member of the House Intelligence Committee than Adam Schiff," said Rep. Denny Heck, D-Wash.
'More than circumstantial evidence'
The Nunes affair damaged the credibility of the House Intelligence Committee investigation, but Schiff said he's confident the probe is moving forward again under Rep. Mike Conaway, R-Texas.
Schiff suggested he has seen the sort of evidence a prosecutor would submit to a grand jury at the beginning of an investigation. He alluded to "more than circumstantial evidence" of collusion between the Trump campaign and Russia, while careful not to discuss the classified details, which would be illegal. Schiff also spoke of direct evidence of deception.
Questions about Michael Flynn
Schiff, in an interview, highlighted Trump's former national security adviser, Michael Flynn, as the most flagrant example of deception. He questioned why Trump took nearly three weeks to fire Flynn after the president knew Flynn lied to top administration officials and the vice president.
"If the reports are accurate and Flynn had a conversation with the Russian ambassador and lied about it — and that conversation was on the subject of the sanctions that the Obama presidency imposed on Russia over their hacking on behalf of Mr. Trump — then that is serious business," Schiff said.
Prosecuted espionage case in 1990
Schiff describes his life as frenetic and compares it to his experience preparing for trials. As an assistant U.S. attorney in Los Angeles he led the 1990 prosecution of FBI agent Richard Miller, convicted of passing documents to the Soviet Union in return for promises of $65,000 in gold and cash.
"My phones are ringing off the hook," Schiff said. "Most of it is supportive calls. But some of it with a lot of very angry Trump supporters as well."
Schiff said his plan is to run for re-election to the House next year. The graduate of Stanford and Harvard Law School, with a granular appreciation for policy detail, would be in a position to become intelligence committee chairman should the Democrats win a majority in the House.
Came to Washington in 2000
Schiff was first elected to Congress in 2000 after a term in the state Senate. He's made national security and foreign policy his niche in Washington, serving on the Benghazi committee, where he spoke in opposition to Republican efforts to tar Hillary Clinton, the party's 2016 Democratic presidential nominee. He's an outspoken proponent of the idea that military action should require congressional approval.
Schiff is now consumed with the Russia investigation. He said he sees the probe as having historical consequences, and spoke of authoritarian political figures in Turkey, Egypt, Hungary, Poland, France, Germany and elsewhere modeling themselves after Russian leader Vladimir Putin.
"We need to know exactly what the Russians did in the United States in order to protect ourselves in the future and in order to help protect democracies that are currently under assault," Schiff said.