Congress must uphold its constitutional duty and press President Donald Trump on his blatant ongoing effort to undermine government oversight.

On Friday, Trump fired his fourth inspector general in six weeks. This time it was at the State Department, where Steve Linick, an apolitical public servant, was unceremoniously sacked.

Perhaps Trump hoped fewer would notice the most recent affront on the front of a weekend. But the outrage is growing and should be bipartisan, especially among members of Congress who take their oath of office literally.

Linick was fired at the urging of Secretary of State Mike Pompeo — one of the key people the State Department’s inspector general should be independently overseeing.

Initial accounts had Linick reportedly looking into whether Pompeo was having staffers — paid by taxpayers — do personal tasks such as walking his dog and picking up dry cleaning. There also have been questions raised about travel involving Pompeo’s wife, Susan, who has no formal State Department role, and by the secretary himself, who has frequently flown on the State Department plane to his home state of Kansas (not exactly a foreign policy priority). The state has an upcoming competitive U.S. Senate race that Majority Leader Mitch McConnell has urged him to enter.

But potentially far more consequentially, Linick was also investigating Pompeo’s decision last year to issue an emergency declaration (and thus bypass Congress) to approve billions of dollars in arms sales to Saudi Arabia and the United Arab Emirates.

Congress had objected to the weapons sales due to Riyadh’s role in the war in Yemen, which has devolved into the world’s worst humanitarian catastrophe, as well as ongoing questions about Saudi Crown Prince Mohammed bin Salman’s suspected role in the killing of Saudi dissident and journalist Jamal Khashoggi, who was a U.S. resident at the time of his brutal slaying.

In a statement, Rep. Eliot Engel, a New York Democrat who chairs the House Foreign Affairs Committee, said that Linick’s office “was investigating — at my request — Trump’s phony declaration of an emergency so he could send weapons to Saudi Arabia. We don’t have the full picture yet, but it’s troubling that Secretary Pompeo wanted Mr. Linick pushed out before this work could be completed.”

No one in fact has the full picture of wrongdoing by Pompeo, if any exists. But that’s why government agencies need oversight. It’s especially important for the State Department, whose envoys travel the world to urge transparent, clean governance. Firing any inspector general — let alone four of them — sends all the wrong diplomatic and democratic signals.

Trump’s campaign to undermine oversight extends beyond the inspectors general. After whistleblower Dr. Rick Bright, the former director of the Biomedical Advanced Research and Development Authority, appeared on “60 Minutes” Sunday, Trump tweeted: “This whole Whistleblower racket needs to be looked at very closely, it is causing great injustice & harm.”

Legitimate whistle-blowing is a patriotic act, not a racket. To steel themselves against the president’s rage, perhaps Senate Republicans should heed the words of two of their GOP colleagues: Iowa’s Chuck Grassley and Utah’s Mitt Romney.

On Monday, Grassley, in his role as chair of the Senate Finance Committee, formally requested that the president “provide a detailed reasoning” for Linick’s removal, as well as respond to a similar, previous request on the removal of Intelligence Community Inspector General Michael Atkinson.

“IGs are intended to be equal opportunity investigators and are designed to combat waste, fraud, abuse, and misconduct without regard to political affiliation. They are the ultimate swamp drainers,” Grassley wrote in his letter to Trump.

In a Monday tweet, Romney said: “The firings of multiple Inspectors General is unprecedented; doing so without good cause chills the independence essential to their purpose. It is a threat to accountable democracy and a fissure in the constitutional balance of power.”

It’s time for all lawmakers — Republicans in particular — to put country over party and uphold their constitutional oversight duty on an administration that repeatedly rejects any checks on its power.