By Darren Samuelsohn and Natasha Bertrand, Politico–

Robert Mueller testified more than 60 times on Capitol Hill during his dozen years as FBI director, but none of those hearings packed anywhere near the amount of anticipation, partisan rancor, or political stakes as his appearance promises to on Wednesday.

And the former special counsel has relied heavily on one man to help him navigate this Washington landmine — Jonathan Yarowsky.

Over four decades as a Beltway attorney, Yarowsky offered impeachment advice to Bill Clinton, and worked for a lawmaker who Richard Nixon once called the “executioner.” He oversaw an unsuccessful push to get a 1990s-era Attorney General Bill Barr to appoint an independent counsel to probe the George H.W. Bush administration’s pre-Gulf War Iraq policies, and he handled fist-pounding document requests from Congress during the contentious Clinton years. Essentially, he’s been a part of some of the biggest “gate” controversies since Watergate — Iraqgate, Whitewatergate, Travelgate, Filegate.

And now, he’s a late entry to Russia-gate.

The 70-year-old lawyer who is a partner at WilmerHale, Mueller’s old law firm, has handled the drawn-out negotiations with House staffers over the contours of Mueller’s testimony. And he’s helped Mueller navigate a toxic Capitol Hill environment that is far more partisan than what the former Russia investigator experienced when he last testified there six years ago as FBI director.

Thanks to Yarowsky, both House Democrats and Mueller have made concessions. Initially, Mueller stated he did not want to testify at all, but facing the reality of a subpoena, the special counsel’s representative has been able to limit his latest client’s appearances before two panels to five hours. And notably, none of Mueller’s testimony will be behind closed doors — a precarious situation that would have allowed lawmakers to later skew his statements publicly.

“He’s the right guy to get. He understands the sand traps as well as anybody,” said Julian Epstein, who replaced Yarowsky in the mid-1990s as the Democrats’ top counsel on the Judiciary Committee. “He’s a good insurance policy to make sure the dialogue beforehand is what it should be.”

“Sounds like a wise move for Mueller to have such a Sherpa,” added Georgia Rep. Hank Johnson, a senior Democrat on the House Judiciary panel who will be among the first to question Mueller.

Of course, Mueller is not a man who needs a roadmap to ready himself for Congress. A half-dozen people who know the long-time lawman described a studious and sober preparer who would conduct practice sessions before legal showdowns, hunker down by himself to go through notes and receive briefers one-by-one ahead of even routine oversight hearings.

But Mueller’s testimony this week will be his first as a private citizen. That means he’s without the deep bench of resources he had during dozens of Capitol Hill appearances as the FBI director under both Republican and Democratic presidents. Now, Mueller is relying on people like Yarowsky and a core group of top aides who were among his earliest hiresin the Russia probe — longtime chief of staff Aaron Zebley and James Quarles, who took a lead role during the investigation working with lawyers for President Donald Trump and the White House.

While Zebley and Quarles are there to prep Mueller on the detailed and barbed questions he’s likely to get about his team’s final report, Yarowsky has been there to line up the logistics and offer other Capitol Hill guidance.

Perhaps most importantly, Yarowsky maintains lasting connections to the Judiciary Committee. He spent more than a dozen years as one of the panel’s top lawyers.

His boss for much of the time was Rep. Jack Brooks, the panel’s chair from 1989 to 1995. Brooks was a famous firebrand in Washington, intimidating to even the most bludgeoning of lawmakers. The Texas Democrat drew Nixon’s ire for his leadership role in the committee’s impeachment hearings and a 1977 Washington Post article quoted one of Lyndon B. Johnson’s former aides calling Brooks as “one of the few men LBJ was ever afraid of.”

Yarowsky’s work on the Judiciary Committee gave him ties to all sorts of figures who now run both Capitol Hill and the Trump administration.

He was an early boss for Perry Apelbaum, who has since risen to become the committee’s Democratic staff director and general counsel. And he was part of a Democratic team that clashed with Barr, who was serving his first stint as attorney general under the first president Bush.

The biggest stand-off with Barr came when the attorney general rejected a House Judiciary Committee request for an independent counsel probe into whether the Bush administration broke the law in the lead-up to the 1990 Iraq war. Barr’s refusal was the subject of outrage on the left — columnist William Safire called him the “Coverup–General” — and even led to calls for his impeachment from the lawmakers Yarowsky worked with.

Intriguingly, Yarowsky also had a hand in reauthorizing the independent counsel statute that governed the investigations into his future boss, Bill Clinton. And as those probes picked up steam, Yarowsky moved to the White House to work for Clinton. He arrived right after the Newt Gingrich-led GOP wave in 1994 that ushered in a new era of enmity between Congress and the administration.

Suddenly, Yarowsky, now a special counsel to the president, was on the other side, fielding demands from both Congress and independent counsel Kenneth Starr. They were looking into Bill and Hillary Clintons’ Whitewater real estate deals from the 1970s in Arkansas. And they also were training their focus on the White House itself, pressing for details on everything from the firing of White House travel office staffers, also known as “Travelgate,” to allegations the Clinton team improperly accessed FBI security clearance documents, also known as “Filegate.”

Sam Sokol, a former White House colleague who later worked with Yarowsky in private practice, said Yarowsky was the “key interface” between the GOP investigators, Clinton’s White House lawyers and his legislative affairs office during this time period.

“Basically, he spoke all three languages and could help folks with very different backgrounds and perspectives solve problems and get things done,” he said.

Eventually, Yarowsky shifted over to manage judicial nominations in Clinton’s second term, taking him out of the direct line of fire. But according to his former colleagues, Yarowsky remained a frequent informal adviser for Clinton as impeachment turned from a Republican talking point into a reality.

After the Clinton years ended, Yarowsky became a familiar lobbying face on Capitol Hill, working for everyone from Microsoft to the NFL Players Association and meeting with lawmakers and staffers across the political spectrum.

In sum, Yarowsky has spent decades at the intersection of presidential scandal, special counsel fights, impeachment and heated congressional probes — all factors set to collide on Wednesday. That makes him the ideal Mueller Sherpa, according to those who know him.

“Jon is going to avail himself of those constant contacts,” said Ted Kalo, another former top House Judiciary Committee lawyer. “This is a guy who has spent almost the entirety of his career attending congressional hearings and observing how Congress works. Jon is going to have a very unique ability to not only be a person who is able to leverage his relationships, but he’s able to forecast and prepare a person for what a hearing is going to feel like.”

Yarowksy did not respond to requests for comment about the role he’s playing with Mueller, which first surfaced when his name was listed as the lone contact for the former special counsel at the bottom of the congressional subpoena the Judiciary Committee issued for his testimony last month.

During the Mueller probe, Yarowsky wasn’t on anyone’s radar. But he was tuned in. During a panel discussion on Watergate last October in Ames, Iowa, Yarowsky, making a rare public appearance, described the similarities and differences between the scandal that ended Nixon’s presidency and the Mueller probe.

While both focused on potential obstruction of justice and the firing of senior law enforcement officials, he said that the country — and especially Congress — are in much different places politically today. He noted, for instance, how few moderate Republicans and Democrats serve on Capitol Hill today.

The resulting “interpersonal chemistry,” he said, is “why you saw incredible investigation and bipartisan action back then.”

Yarowsky’s newest client is no stranger to Capitol Hill. Mueller appeared dozens of times while holding some of the most high-ranking jobs at DOJ, including his Senate confirmation hearing to be FBI director in July 2001 and a session to discuss intelligence gathering and counterterrorism in the wake of the Sept. 11, 2001, terrorist attacks.

His methods for preparing for big moments are unlikely to change, people who know Mueller say. He’s long used the same routines for any big moment — rigorous studying, in-depth briefings, and mock sessions to mimic the big event, whether it be a hearing or legal showdown.

“Even for relatively simple presentations, Mueller would prepare relentlessly,” said Chuck Rosenberg, a DOJ veteran who worked closely with Mueller and has known him for two decades.

Rosenberg recalled briefers from all corners of DOJ and FBI “lining up” outside Mueller’s conference room to go over various topics for something as simple as annual congressional oversight hearings, which are often a low-key affair.

“He doesn’t like public speaking,” Rosenberg added. “But he prepares assiduously and is extremely credible because he doesn’t try to spin, he doesn’t speculate and he doesn’t hypothesize.”

As FBI chief, Mueller’s staff would work on building out talking points and crafting an opening statement. They’d gather background material on what members wanted to talk about and brief Mueller directly on those findings. They’d also track the latest media stories, fact-checking them along the way, to keep him up to date.

“His style is ‘just the facts, ma’am,’” said Joe Campbell, a 25-year FBI veteran who worked for Mueller during his entire dozen-year stint as FBI director.

“He wants to be helpful, doesn’t want to obfuscate or create the appearance of obstruction. I’ve never known him to fall flat. He’s always been very direct and clear-thinking in his answers, and has tried to help members understand key points,” Campbell added.

Sometimes, Mueller would simply hide away by himself to pore over memos. “I’ve seen the door closed,” said Melinda Haag, who served under Mueller when he was U.S. attorney in Northern California. “He prepares extensively for everything, so this would be no exception.”

Wednesday’s back-to-back hearings before the Judiciary and Intelligence committees will present a whole new set of challenges for Mueller and his team, though. For starters, Mueller will have to address 63 total lawmakers between the two panels, although there is a little overlap. He’ll also need to have a facility with two distinct volumes of his 448-page report — one which details Russia’s election interference efforts and the other which lays out Trump’s potential efforts to obstruct justice.

As a witness, Mueller is more no-nonsense than natural storyteller. His former colleagues have even joked about his unyielding solemnity in front of Congress.

“The first time I testified with him, you know, he sat there like a choir boy and never moved,” recalled George Tenet, the former CIA director, during Mueller’s 2013 retirement ceremony from the Justice Department. “I said, you know, ‘Bob you have to learn how to emote a little bit.’ He said, ‘I can’t emote. I’ve been trained as a prosecutor. We’re not allowed to show emotion.’”

Tenet said he even tried to get Mueller to crack a smile during hearings by covering his mouth with his hand and whispering something that no one else could hear.

“Everybody thinks we’re saying something profound to each other at the moment. Well, Bob and I would be in the middle of a testimony and I would cup my hand and look and say something to Mueller like, ‘Bob isn’t that the dumbest question you’ve ever heard in your life?’”

“‘Shut up,’” Mueller replied, according to Tenet.

Regardless of how formal Mueller appears during Wednesday’s hearings, the scene will be the “public spectacle,” Barr has predicted.

Pro-impeachment lawmakers say they’re optimistic the hearing will help them swell their own ranks, while Democratic leaders are trying to keep the focus on the special counsel’s findings and away from political theatrics. GOP members, for their part, want to pointedly question Mueller to cast doubt on his work’s integrity.

Yarowsky is well aware of these dynamics. At the panel discussion on Watergate last October hosted by Iowa State University, he set the scene for what’s unfolding in Congress as lawmakers inch toward trying to impeach Trump.

The “one thing” Watergate taught him, Yarowky said, “is that there’s absolutely no political purpose or benefit to mingle politics with what you do with impeachment.”

Ousting Nixon may have seemingly boosted the Democrats in the short term — the party won big in the 1974 midterms and took back the presidency in 1976 — but he recalled how the GOP came roaring back in 1980, as conservatives slowly started to cull moderates from the Republican ranks.

“They built a core group of very conservative identity in the Republican party which now I think has led to the current administration and the point of view, good or bad,” he said.

And he repeated the now-familiar refrain about how the GOP attempt to oust Clinton in the late 1990s only made him more popular as a lame duck president and into his retirement. Essentially, Yarowsky argued you can never tell what the long-term political ramifications will be from impeachment.

“My only point: Don’t assume there’s a political angle,” Yarowsky said, “though that’s what you’re going to hear all the way.”