With his department under an intensified attack from the White House and its Capitol Hill allies, Rod Rosenstein vented his frustration with a joke.

In the course of discussing the Justice Department’s approach to corporate crime, Rosenstein, the deputy attorney general perpetually on the verge of being fired, said current policy discourages “piling on” penalties. He paused to prepare his New York audience for the punchline. “The dictionary defines piling on as joining with other people in criticizing someone, usually in an unfair manner,” Rosenstein said. “I also have experience with that.”

It was late on a Wednesday morning that began, like so many for Rosenstein, with President Trump tweeting about how the “Criminal Deep State”—meaning the Department of Justice, the FBI and, derivatively, Robert Mueller’s investigation—engaged in a “major SPY scandal” against him, and threatened unspecified consequences. (“What goes around comes around!”) For good measure, the president added, like a catch phrase : “WITCH HUNT!”

Rosenstein, scheduled to speak to a corporate New York audience at a forum sponsored by Bloomberg Law, responded with subliminals .

The deputy attorney general had just come from the New York office of the FBI, he noted, without mentioning that it’s the favorite FBI field office of new Trump attorney Rudy Giuliani. (Or, at least, it used to be.)

“One of the things that sometimes gets lost in the endless commentary about law enforcement,” Rosenstein said, “is that some of the most patriotic and public-spirited Americans work alongside me in the Department of Justice.” He didn’t need to say who issues that endless commentary.

“If you walk into any branch of the Department of Justice anywhere in the country,” Rosenstein continued, “you will find some of the most decent, ethical, honorable and admirable people you could ever hope to meet.”

Nor did Rosenstein need to say why he felt compelled to issue basic platitudes defending the character of federal prosecutors and FBI agents. Over the past week, Trump, aided by pivotal Republican allies on Capitol Hill, has intensified his attacks on them over the Russia investigation, pushing a counternarrative of victimhood that depends on portraying Rosenstein, a Republican who Trump made deputy attorney general, and his colleagues as Democratic hacks determined to frame the president.

It was only a year ago that Rosenstein, a career federal prosecutor, handed Trump a pretext for firing FBI Director James Comey, an act considered craven by many of his longtime colleagues and observers. But it wasn’t long until the ire of Trump and his allies turned on Rosenstein, who soon empanelled Mueller as special counsel over the Russia investigation.

By December, House Republicans were demanding Rosenstein act against Mueller, but Rosenstein refused. Trump asked Rosenstein if he was “on my team” after the deputy attorney general had tried to get White House aid against Trump’s House GOP allies. A month later, House intelligence committee Devin Nunes had included Rosenstein in a tendentious, high-profile memorandum alleging surveillance abuses at the heart of the Russia inquiry.

Nunes’ gambit failed, but the vilification of Rosenstein has continued. Last month, House conservatives drafted articles of impeachment against the deputy attorney general, ostensibly for stonewalling on turning over documentation related to the FBI inquiry into the Trump campaign. Trump reacted by implying, yet again, that he might fire his hand-picked deputy attorney general. All of that prompted Rosenstein, who has mostly taken a low public profile to say that the Justice Department—and, by extension, he himself—won’t be “extorted.”

The political reality underlying the attacks on Rosenstein is that he oversees Mueller. Intimidating him or firing him is the threshold maneuver to rein in the special counsel. And as Trump’s new attorney, Giuliani, has taken a more pugnacious stance with Mueller, Trump has intensified a battle with the Justice Department.

The latest maneuvering by Trump’s allies to discredit the Mueller inquiry is an attempt by Nunes to get Justice Department material on an FBI informant who, starting in the summer of 2016, met with Trump campaign officials George Papadopoulos, Carter Page, and Sam Clovis. U.S. intelligence officials have warned that the material could endanger the informant, who reportedly is a professor named Stefan A. Halper.

Yet Trump, without evidence, has portrayed this typical investigative practice as a nefarious effort by what he called the “Obama FBI” to put “spies in my campaign”—and for a week has amplified that dubious portrayal to craft a narrative of an investigation that was politically corrupt from the start. On Thursday, he termed it “Spygate.”

By resisting Nunes’ subpoena, the Justice Department once again came in the crosshairs of the House GOP and the president. Trump on Sunday “demanded” the department investigate itself over whether his campaign had been “infiltrated or surveilled.” Rosenstein quickly punted that call to the inspector general—a move that had the effect of preserving the political status quo, since the inspector general is already examining FBI and department behavior related to the 2016 election.

In his New York speech on Wednesday, Rosenstein—again without ever mentioning why, or needing to—praised the inspector general’s office as part of a critical series of institutional safeguards against “wrongdoers” of the sort that Trump is seeking to highlight. He called them “nonpartisan” and lingered on the word.

“The inspector general’s federal agents, attorneys, and other officials are governed by executive branch confidentiality rules. Federal statutes allow them to review material that is not appropriate for disclosure outside the Department and prohibit them from leaking,” Rosenstein said, noting that the inspector general is empowered to make criminal referrals.

On Thursday, Nunes and ally Rep. Trey Gowdy will meet to discuss the Halper issue with FBI Director Chris Wray, Director of National Intelligence Dan Coats, and senior Justice Department official Ed O’Callaghan. Rosenstein is conspicuously not attending. Nor have any Democrats been invited, which prompted Nunes’ Democratic counterpart Adam Schiff to say that the meeting is intended to ultimately deliver sensitive material on the informant “to [Trump’s] legal team,” something he called “a serious abuse of power.”

Rosenstein didn’t go remotely that far, nor was he remotely explicit. The corporate-compliance portion of his remarks carved out space to praise Trump and Attorney General Jeff Sessions. By discussing the consensus Republican territory of not overly burdening corporations, even in a criminal context, Rosenstein could inhabit a world in which he was firmly in step with the administration in which he serves.

But toward the end of his 23-minute speech, the deputy attorney general sounded like a man at the end of his tether. At times appearing as if he was describing himself, Rosenstein nodded to the “discipline” and the “need” necessary, “when we make an allegation of wrongdoing, to prove it beyond any reasonable doubt to a judge and jury with credible, admissible evidence. That gives us a very powerful incentive to seek the truth, and only the truth, wherever it may lead us.” Once more he let the contrast hang in the air.

Rosenstein quoted legendary attorney general, Nuremberg war-crimes prosecutor, and Supreme Court justice Robert Jackson about building a “Cathedral of Justice,” a legacy he described his colleagues as carefully protecting and strengthening. It was both a conspicuous departure for a speech about the Justice Department’s relationship with corporate America, and an inevitable one.