After decades of ostracizing much of Washington with his hardline views and sharp elbows, John Bolton now finds himself more popular than ever.

Everyone wants to talk to Bolton amid the inquiry into President Donald Trump and his associates’ pressure campaign against Ukraine, a scheme Bolton, then the national security adviser, reportedly likened to a “drug deal.” On Twitter, some already have welcomed him to the “resistance”; others speculate he’ll end up one of the “heroes” of the impeachment story, a star witness. High-profile agents want to sell his book. And now, it appears Congress wants to hear from Bolton, too—his lawyers are reportedly arranging a deposition.

But no one should get too excited about what Bolton will ultimately say. If he testifies before the congressional inquiry, Bolton will bring more to the hearing room than recollections about the Trump White House. A look at his career—which has been animated by the fight for a strong presidency, especially on matters of foreign policy—suggests his testimony is unlikely to be everything the resistance wants to hear.

Like many in his generation of Republican foreign policy operatives, Bolton began developing his views about the power of the presidency at its nadir. After serving as an intern in Richard Nixon’s White House and graduating from Yale Law School, Bolton opted not to return to an administration mired in Watergate and instead headed into private practice. In his first days as an associate at Covington & Burling, Bolton watched as Nixon was “forced to resign in disgrace,” as he later put it in a memoir.

Bolton’s phrasing was purposeful: In the Watergate era, he saw how an “overreacting” Congress, as he later called it, could limit the president’s authority—for example, with the War Powers Act and independent counsel statute. On campaign finance in particular, Bolton soon made a name for himself and (a decent living) during Jimmy Carter’s administration, litigating against some of the perceived congressional overreach.

Bolton continued that fight when he joined Ronald Reagan’s Justice Department. As assistant attorney general for legislative affairs, Bolton handled some of Congress’ investigations into the Iran-Contra affair, in which some White House aides sold weapons to Iran and then illegally funneled the proceeds to the so-called Contras battling the socialist government in Nicaragua. A decade after Watergate, the scandal set off a firestorm of investigations and questions about the power of the presidency.

Even though the president took responsibility for the mess and did not invoke executive privilege during it, Bolton considered the whole inquiry an “assault on the Reagan presidency,” he later wrote. At the time, he accused special prosecutor Lawrence Walsh, a former judge appointed to investigate Iran-Contra, of using a “wacko theory” of law and spending too much money.

Bolton was not alone: Then-Congressman Dick Cheney opposed the investigation and any attempts to interfere with presidential foreign policy prerogatives. To Cheney and Bolton, Iran-Contra became an important front in the bigger war to rebuild the power of the presidency. In testimony before the Senate Governmental Affairs subcommittee, Bolton called the post-Watergate Ethics in Government Act, which included appointments of independent counsels, “unconstitutional.” He argued in the hearing that, “under the constitutional system of separation of powers, the president or his delegate, must retain the unfettered ability to direct and supervise all executive officials.”

Bolton did not even believe Congress should investigate an actual drug deal. Upon reports that allies of the Contras were also involved in drug running, then-Senator John Kerry sought to get to the bottom of it, only to run into resistance from Bolton. The assistant attorney general stalled requests for information. Then, according to reports by journalist David Corn and others, Bolton worked with Republican members of the committee to end the investigation. One Senate staffer claimed Bolton had “tried to torpedo” the attempt at oversight.

After the Reagan presidency, Bolton, Cheney and their allies continued a long, patient crusade to strengthen the presidency, especially with regard to foreign policy. During the George W. Bush administration, they “supported vigorous executive authority to protect our national security after the 9/11 attacks,” as Bolton and a fellow lawyer later wrote. That included Bolton’s own ambassadorship at the United Nations, which was only achieved through a recess appointment Bush made after Senate Democrats had blocked the nomination in Congress.

As a result of intellectual, administrative and legislative efforts by Bolton and other conservative lawyers, lobbyists and scholars, the presidency recovered much of the authority it had lost after Watergate and Iran-Contra, arguably becoming even more powerful during the post-9/11 wars. Bolton’s long-term belief in the power of the presidency, in fact, is one reason he could work for Trump in the first place, despite his resistance to several Trump policies, on North Korea, Iran and Afghanistan: Bolton could defer, however grudgingly, because he has long believed the president gets the ultimate say.

Although Bolton is now free from Trump, having left the White House in September after 17 months on the job, he faces a similar challenge in the Ukraine investigation, which is shaping up to be in part about the president’s authority over foreign policy. Bolton again has to decide whether to give up on long-held beliefs—this time about the power of the presidency—to be popular in Washington. Of course, subpoenas have a way of making decisions easier. Bolton could just go along to get along, deciding to exact some revenge on Trump with a deposition filled with a detailed litany of any presidential crimes and misdemeanors.

But subpoenas rarely change anyone’s mind, let alone one as disciplined and devoted as Bolton’s. The power of the modern presidency is Bolton’s career legacy, a project he has been working on longer than North Korea, Iran or any one issue. When Trump and his defenders question the legitimacy of today’s inquiry, they’re not just speaking Bolton’s language—they’re using his talking points. Even if Bolton soured on Trump or disagreed with his Ukraine scheme, the current resident of the White House is unlikely to have changed the former national security adviser’s belief that the United States needs a strong commander in chief.

For that reason, Bolton’s decision to consider providing a deposition is as momentous as it surely was tortured. His testimony will likely be the same. Such discomfort might be the reason for the awkwardness of the leaked line that so elated Twitter last week. According to reports about former National Security Council staffer Fiona Hill’s private congressional testimony, Bolton, her boss, apparently wanted it clear, “I am not part of whatever drug deal [U.S. Ambassador to the European Union Gordon] Sondland and [White House chief of staff Mick] Mulvaney are cooking up” in Ukraine. Again, the phrasing matters: If Sondland and Mulvaney were doing the cooking, the president wasn’t.

We should expect more of those sorts of phrases, distinctions and qualifications from Bolton if he testifies. As he did during his tenure as national security adviser, Bolton will seek to keep his hands clean and stay true to his principles, even if he is participating in something that challenges them. Ultimately, Bolton might be willing to undermine a president for pursuing an operation that would appear to violate Bolton’s policy preferences and view of the law. But he is unlikely to undermine the presidency—and principles like executive privilege—any more than he has to.

Toward the end of the Bush administration, in response to a decision about North Korea that Bolton opposed, he wrote, “Nothing can erase the ineffable sadness of an American presidency, like this one, in total intellectual collapse.” Whenever Bolton finally has his say about Trump’s Ukraine scandal, it is likely to be uttered not in anger but in sorrow, not gaily but grudgingly, and in the narrowest way possible. For Bolton, there is something sadder than a presidency’s decline: the collapse of the office itself.