Rep. Adam B. Schiff (Calif.) right, ranking Democrat of the House Permanent Select Committee on Intelligence, and Chairman Devin Nunes (R-Calif.) at a news conference in Washington on March 2, 2017. (Tom Williams/CQ Roll Call/AP)

There was a time not too long ago when the Republican chairman and the top Democrat on the House Intelligence Committee were pals. Even as they set to work last year on the panel’s probe into Russian meddling in the 2016 election, they enjoyed a “collegial working relationship” and “something of a bromance,” as the San Jose Mercury News put it.

Since then, Rep. Devin Nunes (R-Calif.) and Rep. Adam B. Schiff (D-Calif.) have transformed into bitter rivals, each accusing the other of letting partisan loyalties cloud his judgment on the most consequential political scandal in a generation.

Months of tension reached new heights late Wednesday, when Schiff blasted Nunes for changing language in a secret memo alleging law enforcement abuses in the Russia investigation before sending it to the White House for approval of its release to the public.

Colleagues criticize each other on Capitol Hill all the time. But rarely does a member blow the whistle on another lawmaker in such dramatic fashion in full public view. It underscored the high stakes of the struggle over the Russia investigation now consuming Congress, the White House — and two once-cooperative colleagues.

In a letter to Nunes, Schiff said the controversial memo was “secretly altered” without Democrats’ consent and called on Nunes to withdraw it, as The Washington Post reported. A spokesman for the committee’s Republican majority called the memo’s release “procedurally sound” and said the edits were “minor.” To “suggest otherwise is a bizarre distraction from the abuses detailed in the memo,” the spokesman said.

It was the latest and one of the most heated clashes between Schiff and Nunes in the months since Congress and special counsel Robert S. Mueller III opened their probes into whether the Trump campaign coordinated with the Kremlin to influence the 2016 election.

The two lawmakers — one a Harvard-educated lawyer, the other a third-generation cattle farmer — have come to personify opposing sides in the matter, representing two vastly different strains in American politics. Schiff, playing the part of both investigator and spokesman, has forcefully defended the probe, saying American democracy itself is at stake. Nunes, an ardent defender of the White House, has set out to protect a duly elected president and his administration from what he views as a politically motivated witch hunt.

Everything in Schiff’s résumé suggests he is well-equipped for this moment, although both he and Nunes have developed reputations as quiet operators in their 15-plus years in Congress.

The son of a Democratic father and a Republican mother, Schiff, 57, was born outside Boston but spent most of his youth in California. He attended high school in one of California’s wealthiest cities, Danville, studied political science at Stanford University and got his law degree from Harvard.

Schiff seemed destined for public office early on. “I remember, like every kid growing up in Boston, being awed by John Kennedy,” he told the Glendale News-Press in 2000.

After law school, he took a job with the U.S. attorney’s office in Los Angeles. The case that put him on the map was his successful prosecution of Richard W. Miller, said to be the first FBI agent ever to be indicted on a charge of espionage. With Schiff arguing the case, Miller was convicted in 1990 of trading classified documents to the Soviet Union for gold and cash.

Soon after, Schiff turned his sights toward the state legislature. In 1996, after two failed bids for the state assembly, he was elected to the California State Senate, where he chaired the chamber’s judiciary committee. He served a single term, then won an election to the U.S. House of Representatives, unseating a Republican in a district north of Los Angeles in what was then the most expensive House race on record.

In Congress, Schiff was generally known as a mild-mannered centrist who preferred to keep a low profile.

“Schiff is not a bomb-thrower. And he’s not a partisan street brawler,” the Hill wrote of him in 2006. “A fair-faced congressman from Southern California, Schiff is a moderate, a compromiser, a man who chose law school over med school because he thought it would give him greater opportunities to serve the public.”

Nearly a dozen years later, little about his demeanor seemed to have changed. A New York Times story from last March opened: “As attack dogs go, Representative Adam B. Schiff, Democrat of California, is more labradoodle than Doberman, his partisanship disguised by a thick fur of intense preparation, modulated locution and gentle accusations.”

National security has been a primary focus for Schiff for most of his tenure. More hawkish than his counterparts on the issue, he formed a Democratic study group on national security concerns in his second term, as the Los Angeles Times reported in 2005. It was an unorthodox move for a Democrat to make at the time, Will Marshall, then-head of the moderate Democratic Leadership Forum, told the newspaper.

“For a long time, particularly in the House, it has been a little lonely to be a Democrat who specializes in security,” Marshall said. “Members too often regarded it as the other party’s issue. Adam sincerely believes the Democratic Party has to reassert its leadership on national security.”

Little in Nunes’s backstory — a rise from farm boy to head of a powerful congressional committee — points to why he has become a pivotal ally of President Trump on Capitol Hill. Nunes was born and raised as a third generation Portuguese American in California’s rural Central Valley, and his aspirations originally didn’t stretch beyond the cattle yard. “All I wanted to be was a dairy farmer,” he told a group of high school students in 2002.

Nunes grew up working a family farm. “I broke so many tractors, they made me work with the cows,” he told the Hill in 2005. He studied agriculture and agricultural business at Cal Poly San Luis Obispo, before returning to the family soil.

His first stab at elective office came in 1996 when he successfully ran for an open seat on the board of the College of the Sequoias, where he had studied in an associates program. He was only 23.

In 1998, Nunes lost a primary campaign for California’s 20th Congressional District seat. The campaign, however, brought him national attention, in part because of his youth, and in 2001 he was appointed by President George W. Bush as the California director of rural development for the U.S. Department of Agriculture. A year later, he tried again for a House seat, this time winning. He was 29.

“Once I got into politics in 1996 I never thought I couldn’t do it,” Nunes told the Hill. “I don’t worry about what other people think. I do what I think is right. I’m not very shy.”

Politically, Nunes’s beliefs run along the standard tracks of GOP conservatism. “Restoring the Republic,” his 2010 book, was a mix of boilerplate free-market advocacy and big government criticism, with Nunes arguing that the biggest threats to America lie in the “the convergence of big government, big business, and the radical left in Washington.” The government, Nunes warned, aims to “take power away from individuals and give it to politicians and bureaucrats — people who have no idea what it’s like to live in the real world or what the problems of everyday people are like.”

Nunes laid out in the book a strenuous opposition to the “environmental lobby,” which he defined as the “well-funded interest groups that pursue an anti-capitalist, anti-economic growth, and anti-democratic agenda that aims to bring about a green utopia.”

On Capitol Hill, Nunes jumped to high-profile positions on the House Ways and Means Committee and the House Intelligence Committee. In 2010, Time magazine named him one of Washington’s “40 Under 40.” But he also stayed below the radar. “You never did hear too much about Devin over the last seven, eight years,” a constituent told Politico in March, adding that the congressman “did a really good job.”

Yet Nunes’s reputation among his congressional colleagues, even fellow Republicans, is not unblemished. During the 2013 brawl within the Republican caucus, Nunes blasted GOP colleagues who were pushing for a government shutdown, memorably calling them “lemmings with suicide vests,” according to the New Yorker.

In March, the New York Times’s Frank Bruni reported he had spoken to a Republican insider who described Nunes as an “overeager goofball” who can’t see “the line between ingratiating and stupid.”

Bruni continued: “The insider said that Nunes crossed that line with John A. Boehner, the former House speaker, who gave him the committee chairmanship but grew weary of Nunes’s indiscriminate pep and constant bumming of his cigarettes.”

The House’s Russia investigation shot both Nunes and Schiff to a new level of national prominence. Despite their different party affiliations, the two men seemed to share a mutual respect. “I have always been impressed by him,” Schiff said of Nunes in 2014, the Fresno Bee reported. “He works in a very bipartisan way.”

The apparent respect remained as the hearings started. In March, when the Intelligence Committee held a rare public hearing with then-FBI Director James B. Comey, Nunes gave Schiff a generous 15 minutes to make an opening statement — time the Democrat used to argue that a full-throttle probe of links between the Trump campaign and Russia was justified.

Schiff says he didn’t seek out the spotlight, but that he was leading the charge because he felt like American democracy is at stake. “This is the political equivalent of [9/11] in magnitude,” he told The Post in an interview at the time.

“I think my role is to try to help the Democratic Party to make this investigation thorough and to make it nonpartisan,” Schiff said. “Sometimes that’s playing the role of diplomat, and other times that’s using the public spotlight to push the investigation forward. … If we issue a report where Democrats find one thing and Republicans find another, both sides retreat to their respective corners and nothing gets revealed.”

The relationship began to fray at an accelerating pace in March. The two congressmen held a joint news conference on March 15 announcing that the committee had found no evidence that Trump Tower was wiretapped by the Obama administration — a claim made by Trump in a tweet. “We don’t have any evidence that took place,” Nunes said.

But on March 21, Nunes made a strange late-night visit to the White House, where an anonymous individual provided what was later characterized as evidence of surveillance on the transition team. The next day, Nunes was back before reporters — this time without Schiff.

“What I’ve read seems to me to be some level of surveillance activity — perhaps legal, but I don’t know that it’s right,” Nunes said. “I don’t know that the American people would be comfortable with what I’ve read.”

Schiff blasted back from his own news conference hours later. “The chairman will either need to decide if he’s leading an investigation into conduct which includes allegations of potential coordination between the Trump campaign and the Russians, or he is going to act as a surrogate of the White House,” he told reporters. “Because he cannot do both.”

Facing ethics complaints and claims that he was now compromised, Nunes eventually stepped away from the investigation.

But the conflict between the two congressmen continued to boil — culminating in this week’s battle over the memo.

The four-page document, which the committee voted on party lines to make public, was produced by Nunes’s office and is said to raise questions about whether the FBI abused surveillance laws when it obtained a warrant from the Foreign Intelligence Surveillance Court to spy on Carter Page, a former adviser to Trump’s campaign. Schiff and other Democrats say the memo contains inaccuracies and is a thinly veiled attempt to distract from the Russia probe.

“This is a grave cost for short-term political gain,” Schiff said Wednesday in a Washington Post commentary.

The aggressive attack by Schiff, which challenged the motives of a committee colleague, was a serious escalation, a breach of congressional comity even by the standards of a bitterly polarized Congress.

Nunes and Schiff, once an example of collaboration amid an otherwise fractured House, are now locked in a high-stakes struggle. The relationship will be hard, if not impossible, to repair.

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