It should have come as no surprise that some in the FBI have seen their power as something to be protected and perpetuated through political dirty tricks. This is the agency that was ruled over for decades by the late J. Edgar Hoover, after all. The agency’s headquarters, incidentally, is named after Hoover, who used illegal surveillance to gather unsavory information about many politicians.

Misdeeds, ranging from telling the press Hillary Clinton was guilty of misdeeds but would not be prosecuted to secret groups of FBI officials dedicated to harming President Donald Trump politically, are just what we know about wrongdoing in the agency during the past couple of years. No doubt there is more, hidden under a self-serving veil of secrecy.

In Washington on Monday, the big news was that FBI Deputy Director Andrew McCabe had resigned. He had been expected to retire this spring.

McCabe held a position of power during the period in which some in the FBI decided to interfere with a presidential election. He either knew or should have known about the wrongdoing. But his departure leaves behind an agency where there is a strong suspicion of institutional corruption.

It needs to be cleaned up, and the task is beyond what Trump, even though he is president, can accomplish on his own. Congress needs to get involved.

Do not expect Democrat lawmakers to be very thrilled at that prospect. They should be — because the FBI has been weaponized politically, and that should be intolerable to Americans of all ideological stripes.