The job of inspectors general in government agencies is to investigate corruption and wrongdoing in the federal government, free of political pressure.

Donald Trump has now fired four inspectors since April 3 in what many say is an attempt to stop oversight of Trump's and his administration's alleged corruption and failures.

The latest dismissal came Friday, when Trump informed House Speaker Nancy Pelosi that he was firing the State Department inspector general, Steve Linick.

"There is no form of corruption too small for this administration," Walter Shaub, the former director of the Office of Government Ethics, tweeted on Sunday. "Leave nothing behind. They'll take the doorknobs too if they can figure out how to unscrew them."

Here are the four inspectors general Trump has fired in recent weeks and what they had been investigating.

State Department inspector general Steve Linick

After Trump on Friday announced he wanted to remove Linick from his role as the State Department's watchdog, members of Congress announced that Linick was investigating Secretary of State Mike Pompeo for using an aide to run personal errands.

"Such an action, transparently designed to protect Secretary Pompeo from personal accountability, would undermine the foundation of our democratic institutions and may be an illegal act of retaliation," Rep. Eliot Engel (D-NY) and Sen. Bob Menendez (D-NJ) wrote in a letter to White House chief of staff Mark Meadows on Saturday.

Engel has launched an investigation into Linick's firing.

Republicans who stood up for inspectors general during former President Barack Obama's tenure in office are now acquiescing to Trump's attacks on independent watchdogs.

Wisconsin GOP Sen. Ron Johnson, who chairs the Homeland Security Committee, said on Sunday that the White House had told him the reason for Linick's firing, though he did not say what it was. Democrats in Congress denied having received such information.

Sen. Chuck Grassley (R-IA) said in a statement that no shortcomings on the part of an inspector general "waive the President's responsibility to provide details to Congress when removing an IG. ... Congress requires written reasons justifying an IG's removal. A general lack of confidence simply is not sufficient detail to satisfy Congress."

However, Grassley did not move to stop Trump's dismissals of the previous three inspectors, which were rationalized on similar grounds.

Intelligence community inspector general Michael Atkinson

Michael Atkinson, who was fired on April 3, reported the whistleblower complaint about Trump's dealings with Ukraine to Congress. That report put in motion Trump's impeachment.

"It is hard not to think that the president's loss of confidence in me derives from my having faithfully discharged my legal obligations as an independent and impartial inspector general, and from my commitment to continue to do so," Atkinson said in a statement following his firing.

Trump, seeming to confirm that his dismissal of Atkinson was at least partly due to the elevation of the whistleblower complaint, charged that Atkinson "took a fake report and gave it to Congress."

Multiple government officials, however, confirmed the allegations within the report during the impeachment trial, including that Trump pressured Ukraine to announce investigations into Democratic presidential candidate Joe Biden.

At the time, Grassley issued a statement similar to the one he made Saturday about Linick's dismissal.

"Congress has been crystal clear that written reasons must be given when IGs are removed for a lack of confidence. More details are needed from the administration," Grassley said in a statement on April 4. He did not pursue publicly pursue the reasoning for Atkinson's dismissal beyond that.

Acting Defense Department inspector general Glenn Fine

Less than a week after Trump fired Atkinson, he announced his decision to fire Glenn Fine.

Fine had been tasked with overseeing how the $2 trillion in relief aid Congress passed in response to the COVID-19 pandemic would be spent.

Congress had specifically created the position to oversee the handling of the aid.

The coronavirus relief package contains provisions specifically barring Trump and his family, as well as other members of the administration and Congress, from receiving aid for companies they control. Fine would have been responsible for overseeing the implementation of the aid package.

Trump suggested he didn't trust Fine because he was an Obama-era appointee.

"We have a lot of IGs from the Obama era, and I left them, largely. But when we have reports of bias, and we have different things coming in," Trump said after he fired Fine.

Acting Department of Health and Human Services inspector general Christi Grimm

On May 2, Trump announced he was replacing Christi Grimm, whose office had released a report that found hospitals across the United States had "severe shortages of testing supplies."

That report contradicted Trump's false claims that his administration had done a great job testing people for the coronavirus.

Public health experts say that the process of implementing testing was too slow, and that there still is not sufficient testing capability to make it possible to safely reopen the economy.

Published with permission of The American Independent Foundation.