"In July 27, 1974, the House Judiciary Committee approved three articles of impeachment against Richard M. Nixon. The second article charged that President Nixon abused the powers of the presidency either by using or trying to use federal investigative agencies against his political enemies or by interfering or trying to interfere with lawful investigations by those agencies into his own wrongdoing or that of his subordinates. He tried to get dirt on his opponents through the IRS. He ordered the FBI to conduct investigations of actual or suspected enemies in and outside of the government. He sought to suppress investigations into the growing Watergate scandal. As the fifth specification in the articles of impeachment put it:
In disregard of the rule of law, he knowingly misused the executive power by interfering with agencies of the executive branch, including the Federal Bureau of Investigation, the Criminal Division, and the Office of Watergate Special Prosecution Force, of the Department of Justice, and the Central Intelligence Agency, in violation of his duty to take care that the laws be faithfully executed.
In short, the House Judiciary Committee voted to impeach Nixon because he sought to turn the immense power of the Justice Department and federal criminal investigative agencies against his political adversaries. Although these articles of impeachment were never approved by the full House of Representatives because Nixon resigned before a vote could be taken, it received more votes in committee than any other proposed article. No respectable scholar of the Constitution doubts that directing the criminal justice and intelligence systems of the United States against political opponents, for purposes unrelated to the impartial enforcement of the law or preservation of legitimate national security interests, is among the impeachable “high crimes and misdemeanors” of Article II, Section 4.
Friday morning, President Donald Trump sent out a series of tweets in which he explicitly urged the Justice Department and the FBI to investigate Hillary Clinton and the Democratic Party for a grab bag of supposed offenses—emails deleted from then–Secretary of State Clinton’s private server, the Russia-uranium kerfluffle, activities by Tony Podesta (lobbyist and brother of Secretary Clinton’s campaign manager), and the allegation that officials at the Democratic National Committee worked with Clinton’s campaign to give it a boost over Sen. Bernie Sanders’.
President Trump committed another impeachable offense on Friday.