One federal inspector general, a former Republican congressman, has spent recent weeks lavishing praise on President Trump while attacking the president’s rival, Gov. Gavin Newsom, Democrat of California.

Another inspector general appointed by Mr. Trump has recently singled out Attorney General Letitia James of New York, one of the president’s most hated targets, as the Trump administration withheld funds for her state.

And Mr. Trump has inserted a right-wing operative — a co-author of the conservative Project 2025 document — to take over the inspector general’s office that would be in charge of any internal investigation into his botched repairs of the Lincoln Memorial Reflecting Pool.

During the first year of Mr. Trump’s second term, his approach to dealing with federal inspectors general, who are supposed to be apolitical, was to fire them and slash funding for their offices. But since the mass firings, the president has appointed some government watchdogs with overtly political backgrounds. And they have directed their investigations toward allegations of fraud at the state level, instead of targeting the agencies within the administration that they are supposed to scrutinize.

“The president wanted his own I.G.s,” said Michael J. Missal, who spent nine years as inspector general for the Department of Veterans Affairs. “When you have your own I.G.s, you lose the credibility and integrity of the work. If people think that you’re doing it to support the administration, then the whole concept that was created in 1978 of independent, nonpartisan inspectors general goes away.”

Taylor Rogers, a White House spokeswoman, said Mr. Trump had hired “highly qualified and accomplished individuals” who would carry out his mission of targeting fraud.

The latest example of Mr. Trump’s inserting a political actor into a nonpartisan watchdog role occurred amid public furor over the Reflecting Pool fiasco.

Alarmed over the Trump administration’s botched repairs of the Reflecting Pool and the president’s attempt to falsely blame the failures on left-wing vandals, Democratic lawmakers urged the Interior Department’s inspector general to investigate.

The Trump administration’s response was to insert a right-wing operative to take over the office that would carry out the investigation.

Dennis Kirk was among the authors of Project 2025, a collection of conservative policy proposals published before the 2024 election. The plan to install Mr. Kirk as the Interior Department inspector general sounded alarm bells in the world of government watchdogs and among Democrats on Capitol Hill, and not merely because he could thwart an internal investigation into the Reflecting Pool.

Through a spokesman, Mr. Kirk declined to comment. The White House voiced support for Mr. Kirk in a statement.

Mr. Missal was one of at least 20 inspectors general who were fired or demoted by Mr. Trump in the first six months of the president’s second term. The mass purge, which was accompanied by staff reductions of up to 30 percent in some offices, resulted in inspectors general offices without permanent leaders and a culture of fear that workers could be fired for doing their jobs.

But now, as Mr. Trump fills some of the positions, he has selected people with political backgrounds, and they have made it the mission of their organizations to look outside the Trump administration for fraud and wrongdoing.

Inspectors general, by law, are tasked with preventing and detecting fraud, waste and abuse related to their agency, while promoting efficiency in agency programs and operations. While they are located inside respective federal agencies, they are designed to act independently and in a nonpartisan manner. About half of federal inspectors general are subject to Senate confirmation.

Anthony D’Esposito is a former Republican congressman who Mr. Trump named inspector general for the Labor Department. But, instead of scrutinizing his own agency, he has said publicly that he is working “side by side” with the administrator of the department to find fraud in the states.

In a series of recent social media posts and public appearances, Mr. D’Esposito has heaped praise on Mr. Trump and attacked his political rivals, such as Mr. Newsom. He also gave a speech last week at one of Mr. Trump’s events on Long Island meant to rally support for Republican candidates in the area.

“I have no problem with them going after fraud. I want them to go after fraud,” said Mark Greenblatt, who was the inspector general for the Interior Department before Mr. Trump fired him last year. “It’s a question of whether the I.G. is part of that effort; they are taking themselves out of their role of overseeing the department.”

As for Mr. D’Esposito’s exuberant praise of the president, Mr. Greenblatt said: “It’s just unimaginable that an I.G. would write like that. You’re not supposed to be a cheerleader for the administration.”

Thomas March Bell, a lawyer who worked for Capitol Hill Republicans before Mr. Trump installed him as the inspector general for the Department of Health and Human Services, has gone after Ms. James, one of Mr. Trump’s biggest rivals. The administration suspended millions of dollars in funding for New York after Mr. Bell accused the state of being weak on fraud.

Some watchdogs have still shown signs of independence. The inspector general for the Department of Homeland Security clashed with the department’s former secretary Kristi Noem, for instance, over allegations that she and her deputies had “systematically obstructed” his work.

But there is evidence that the firings and staff reductions have impeded the work of inspectors generals, who are meant to be the eyes of the taxpayers on their respective agencies.

Inspectors general assigned to cabinet-level agencies issued 15 percent fewer audits and 25 percent fewer investigative reports in the first half of fiscal year 2026 compared with the average of the past five years, according to research conducted by the Partnership for Public Service, a nonprofit that works on civil service issues. Five departments issued at least 30 percent fewer audit reports, and five issued at least 30 percent fewer investigative reports.

“The offices with the largest staffing cuts were also the ones with the largest declines in investigative reports,” said Chris Piper, a senior manager with the group.

Still, within the inspector general community, the nomination of Mr. Kirk is considered a pivot beyond merely cutting those agencies. Now, former inspectors general say, they are being politicized.

Mr. Kirk was a former adviser to Tulsi Gabbard when she served as the director of national intelligence, and a staff member at the conservative Heritage Foundation.

The Trump administration’s efforts to rush through repairs to the Reflecting Pool ended in a debacle earlier this year. Under Secretary Doug Burgum, the Interior Department approved no-bid contracts for vendors, citing tight deadlines, in an effort to bypass scrutiny of the renovations, according to a New York Times investigation.

A hastily installed blue lining on the pool began to peel, and new water-purification systems failed to prevent a bloom of algae that turned the pool green — a major embarrassment for Mr. Trump.

The president blamed vandals, but the Justice Department dropped charges against one defendant, telling the court that the contractor was to blame for the problems.

Now Democrats fear that no real investigation will be conducted.

“This is in some ways unsurprising because this was all right in Project 2025,” says Representative Jared Huffman of California, the highest-ranking Democrat on the House Natural Resources Committee who was among the Democrats calling for an investigation. “They laid out the purge of the civil service and the consolidation of these independent entities within the government under executive power, under direct executive power, and then they called for a second step, which was to repopulate all these positions with Heritage-trained political stooges.”

Mr. Huffman noted that in past administrations, including during Mr. Trump’s first term, inspectors general were responsive to requests from lawmakers. But if partisans occupy the roles instead of career professionals, that could change.

“It means the purpose is upended totally,” he said. “You’re not getting a meaningful, independent review of government waste, fraud and abuse. You’re getting another politically weaponized tool for Donald Trump.”