As the impeachment drama has unfolded over the past week, a series of disclosures has illuminated President Trump’s command over key federal agencies, revealing how he has compelled them to pursue his personal and political goals, investigate his enemies and lend legitimacy to his theories about the 2016 election.

The Justice Department has prioritized a probe that the president hopes will discredit a finding by U.S. intelligence agencies that Russia interfered in the 2016 election to help him win. As part of that effort, Attorney General William P. Barr has met overseas with foreign intelligence officials to enlist their aid in “investigating the investigators,” as the right’s rallying cry goes, and dig into the president’s suspicions.

The State Department, meanwhile, has been investigating the email records of as many as 130 current and former department officials who sent messages to the private email account of Hillary Clinton, the former secretary of state and Trump’s 2016 opponent. Secretary of State Mike Pompeo defied Congress on Tuesday by attempting to block the depositions of five department employees called to testify in the impeachment inquiry.

The inquiry itself was sparked by a July 25 phone call in which Trump asked his Ukrainian counterpart to investigate unsubstantiated corruption allegations against former vice president Joe Biden, a leading 2020 Democratic presidential candidate, and his son.

In each of these instances, the president or administration officials have strongly defended their conduct as proper and above board.

But taken together, they illustrate the sweeping reach of Trump’s power and the culture he has spawned inside the government. The president’s personal concerns have become priorities of departments that traditionally have operated with some degree of political independence from the White House — and their leaders are engaging their boss’s obsessions.

“Barr and Pompeo are stuck in the fog machine. They seem captives of the president’s perverse worldview,” said Timothy Naftali, a historian and former director of the Richard Nixon Presidential Library and Museum. “Authoritarian regimes have this problem all the time . . . when all government activity is the product of the id of the leader. But in a republic, that’s unusual.”

Most Republicans have stood by Trump. Sen. Lindsey O. Graham (S.C.), echoing many of them, told reporters it would be “insane” to impeach Trump and said the exchange with Ukrainian President Volodymyr Zelensky was appropriate.

Trump’s moves underscore his transformation as president. He arrived in Washington a neophyte uncertain about how to operate the machinery of government. But now, in his third year in office, Trump has grown confident about exercising power, disposing of aides who acted as guardrails and elevating those who prove their loyalty by following his orders.

As the president said last month after John Bolton’s abrupt exit as national security adviser, “It’s very easy actually to work with me. You know why it’s easy? Because I make all the decisions.”

Trump was sworn in as the 45th president with less governmental experience than any of his predecessors. His advisers tried to tutor him about the three branches of government and the constitutional balance of powers. The general ethos among Trump’s top aides then was to protect institutions and moderate some of the president’s swings — to resist rather than follow his impulses, as described by one former senior White House official, who spoke on the condition of anonymity to share a candid assessment.

Since then, Trump has become more emboldened to make decisions and has systematically dispensed with much of his early team, including former defense secretary Jim Mattis, former secretary of state Rex Tillerson, former White House chiefs of staff Reince Priebus and John F. Kelly, former White House counsel Donald McGahn, former national security adviser H.R. McMaster, former economic adviser Gary Cohn and others.

“I’m not sure there are many, if any, left who view as their responsibility trying to help educate, moderate, enlighten and persuade — or even advise in many cases,” the former senior official said. “There’s a new ethos: This is a presidency of one.”

“It’s Trump unleashed, unchained, unhinged,” this official added. “He continues to go further and further and further, and now I don’t think there’s anybody telling him, ‘No.’ ”

Some of Trump’s closest aides and friends strongly contest the suggestion that he is unbridled and pursuing his personal interests at the expense of the nation. Instead, they cast him as a politician who is curious, at times to a fault, about the investigations into his 2016 campaign and determined to reveal more about those efforts. They shrug off his moves as “Trump being Trump” and part of the president’s showmanship in driving the national political debate as opposed to a possible constitutional reckoning.

“He’s actually very calm,” said one White House official who was not authorized to speak publicly. “He’s not raging. He’s not fuming. He can’t stand what some people write or say on television, sure, but his presidency isn’t consumed by that.”

Sam Nunberg, a former Trump campaign adviser, said the president has long wanted to be the sole driver of his message, with everyone else playing supporting roles — which is how he ran his business and 2016 campaign from his corner office on the 26th floor of Trump Tower in New York.

“He wants to be the one adjusting and taking the lead on where it goes, not adjusting to others,” Nunberg said. “It goes back to how he navigated network TV, the tabloids and business publicity. That’s his playbook.”

Some outside scholars have a different interpretation. Trump’s moves represent a fundamental reorientation of American democracy, said Timothy Snyder, a Yale history professor and author of “On Tyranny,” a resistance guide to what he describes as America’s turn toward authoritarianism.

“Rather than having the boring system we take for granted, where you have laws based on facts, instead you have a personality who makes up his own reality,” Snyder said. “At first, that reality is just confusing and seems to gum up the works, but after a while, the leader starts to draw people into that reality by making them defend it or making them prove it. This is what’s happening here.”

In Trump’s Washington, many administration officials have calculated that if they do not enthusiastically wade into Trump’s riptide of grievances and personal pursuits, they risk being ridiculed or sidelined by the president, as was the case with Bolton, a hawk whom Trump has mocked since his departure as “Mr. Tough Guy.”

The implicit day-to-day charge for many Trump advisers is simple, according to aides and other officials familiar with the president’s Cabinet and West Wing staff: Figure out how to handle or even polish Trump’s whims and statements, but do not have any illusion that you can temper his relentless personality, heavy consumption of cable news or thirst for political combat.

Acquiescence is central to survival. Trump has bonded with aides who take his running complaints about the “deep state” and “fake news” seriously, along with his embrace of people and positions outside of the mainstream. The leading members of Trump’s inner circle dutifully work to address his concerns, sometimes by directing federal resources.

Officials including Treasury Secretary Steven Mnuchin, for example, have worked to block Democratic lawmakers and others from obtaining access to Trump’s tax returns, which he has refused to disclose publicly.

The list of Trump loyalists pulled into his maneuvers begins at the top. Vice President Pence traveled to Europe in early September and met with Zelensky and urged him to address “corruption,” seeming to reiterate the message Trump communicated to Zelensky in July about investigating the Bidens. This was before promised U.S. military aid to Ukraine was released.

Barr’s role in the investigation into the Russia probe’s origins, which is being conducted by U.S. Attorney John Durham in Connecticut, is extraordinary in part because the probe seeks evidence of misconduct within his own Justice Department to support the conspiracy theory — embraced by Trump and advanced on Fox News — that the Russia inquiry was corrupt and predicated on undermining Trump.

Snyder said the investigation Trump sought and Barr is pursuing fits a pattern of behavior in which leaders try to disprove or undermine facts — in this case, the conclusion that Russia interfered in the 2016 election to help Trump win — with other investigations.

“The idea of investigating the investigation is that you cast doubt on the boring factual stuff,” he said. “Even if you don’t win with your adventurous fiction, you also win if your adventurous fiction casts doubt on the boring facts.”

The White House and Justice Department have defended this review of the investigation into possible connections between Russia and members of the Trump campaign as appropriate; Barr told Congress in April that he believed “spying did occur.”

Barr’s interest in the probe is unsurprising to several of his associates, who said this week he is a headstrong and deeply conservative man who at this point in his career has grown disdainful of the Democratic Party, the federal government and the news media, criticizing them in private as biased and skewed against the president.

Trump’s advisers say he respects Barr’s approach and considers him “tough,” especially compared to former attorney general Jeff Sessions, who in 2017 recused himself from the Russia investigation.

“We have a great attorney general now,” Trump said of Barr in July. “He’s strong, and he’s smart.”