Back in 2016, a colleague handed Donald F. McGahn II, then a top legal adviser to the presidential candidate Donald J. Trump, an appeals court opinion that eloquently and powerfully echoed much of what Mr. McGahn saw as the evils of an out-of-control federal bureaucracy.
The opinion from the Denver-based appeals court by the relatively unknown Judge Neil M. Gorsuch suggested it might be time for federal courts to confront the “behemoth” of a longstanding precedent conferring substantial regulatory power on federal officials.
One month later, Mr. McGahn placed Judge Gorsuch on Mr. Trump’s list of potential Supreme Court nominees should he be elected.
Four months later, he was President Trump’s first nominee to the high court.
And over the past week, Justice Gorsuch wrote for the conservative majority on the Supreme Court that made sure the behemoth was slain.
While much of the attention to the conservative-dominated court has been about the sweeping decisions it has made to roll back abortion rights and now greatly expand presidential immunity, that was never the main goal for the architects of the effort to pull the judiciary to the right.
For those who led the drive to place Justice Gorsuch and two other conservatives on the court during the Trump administration, a sweeping series of rulings by the Supreme Court this year that shrank the power of federal agencies was the true victory. Their longtime target, the so-called administrative state, has been beaten back with the overturning of the 40-year-old Chevron doctrine and a flurry of other decisions aimed at reining in federal government reach — just as they envisioned it.
“None of this was an accident,” Mr. McGahn, a partner at Jones Day, said in an interview about the court’s landmark rulings on administrative law — an arcane area but one that was a cornerstone of his campaign to place jurists skeptical of federal power on the bench. “It was a way to corral the runaway bureaucracy to get judges in place who were actually going to read the law as it was written.”
Limiting the power of federal officials was a longstanding goal of members of the Federalist Society, the conservative group seen as an incubator for the type of judges that Mr. McGahn and others sought when they moved to quickly populate the courts with conservative jurists after Mr. Trump’s election.
“Dismantling the administrative state and empowering people who are actually elected to make decisions has been the motivating force” for nearly every “Federalist Society-type lawyer,” Senator Mitch McConnell, the Kentucky Republican and minority leader, said in an interview.
Mr. McConnell spearheaded the judicial confirmation effort in the Senate as majority leader, beginning when he blocked President Barack Obama from filling a Supreme Court vacancy in 2016, and then working hand in hand with Mr. McGahn once Mr. Trump was elected to push scores of his judicial nominees to the bench.
“I think the left thought that all we ever talked about was Roe v. Wade,” Mr. McConnell said. “Frankly, I can’t even remember it coming up. This was the unifying issue,” he said of the attempt to rein in federal agencies.
Mr. McGahn had first grown leery of the extent of agency regulatory power during his own stint as a member of the Federal Election Commission. When he became White House counsel for Mr. Trump, he played a central role in vetting candidates for the Supreme Court and recommending them to the new president.
He searched for potential nominees who had demonstrated a zeal for challenging the reach of federal agencies and backed it up with strong legal arguments and decisions.
“It’s not enough to say the right things in public speeches,” Mr. McGahn said in November 2017 remarks to the Federalist Society, as he laid out his strategy for what had come to be known as deconstructing the administrative state. “Judges must apply those principles in concrete cases.”
Judge Gorsuch had demonstrated his thinking in the 2016 opinion. Brett Kavanaugh, a former White House official sitting on the U.S. Court of Appeals for the District of Columbia Circuit, had what Mr. McGahn considered a long paper trail that put him at the “vanguard of curtailing agency power,” eventually earning him a spot on the Trump Supreme Court contender list as well.
Amy Coney Barrett, a Notre Dame law professor confirmed to the U.S. Court of Appeals for the Seventh Circuit in 2017, did not have the judicial record of the other two, but Mr. McGahn liked what he heard during interviews for the appeals court post.
“She spoke favorably of the work of Gorsuch and Kavanaugh,” he said. “These guys are cut from the same block of wood.”
All three were eventually seated on the Supreme Court over the vociferous objections of Democrats, providing the critical mass of votes for the series of rulings that will mean significant changes in the way agencies exert power. They will also put new pressure on Congress to write laws with less wiggle room for how agencies interpret and enforce them.
Besides the landmark ruling overturning the Chevron doctrine requiring courts to defer to interpretation of laws by federal agencies, the justices also blocked the E.P.A. from enforcing a rule intended to protect downwind states from pollution from neighboring states, a decision with broad implications for other environmental rules. They also required the Securities and Exchange Commission to try fraud cases in federal courts rather than in-house tribunals, another consequential shift.
Then on Monday, the Supreme Court struck a significant blow against agency power in another ideologically divided decision, ruling that a six-year time limit on challenging agency regulations should begin when it affects a company, not six years from when it was put in place.
“I think this is an issue that has the potential over the long term to kind of rearrange the power between those who are actually elected and those who are doing whatever they want to,” said Mr. McConnell, referring to lawmakers versus federal regulators.
The string of anti-regulatory rulings has alarmed both the liberal members of the court and Democrats who see the potential for unraveling decades of agency work to protect the health and welfare of Americans.
In a dissent, Justice Katanji Brown Jackson warned that the decision could unleash “a tsunami of lawsuits against agencies” and had “the potential to devastate the functioning of the federal government.”
Senator Chuck Schumer, the New York Democrat and majority leader, said the justices had “once again sided with powerful special interests and giant corporations against the middle class and American families. Their headlong rush to overturn 40 years of precedent and impose their own radical views is appalling.”
But Mr. McGahn said the rulings should reset the federal regulatory regime and restore power to its rightful place in the legislature.
“This puts Congress back in the driver’s seat,” he said. “It also gives them a real responsibility that they have to start doing their job and legislate with some sort of specificity.”