Impeachment is the process used by a legislative body to bring charges of wrongdoing against a public official. Basically, it is the indictment of an appointed or elected public officer on serious criminal charges. The legal basis for impeachment is stated in Article II, Section 4 of the United States Constitution:
"The President, Vice President and all civil Officers of the United States, shall be removed from Office on Impeachment for, and Conviction of, Treason, Bribery, or other high Crimes and Misdemeanors."
The House of Representatives is the only body that can impeach federal officials. If a federal official is impeached, a trial by the Senate follows, which is where guilt and the potential removal from office is debated. It is important not to confuse impeachment with conviction. Impeachment is just a formal accusation; it is only the first step in removing a public official from office.
The idea of impeachment in the United States is usually discussed in reference to the president, although only two presidents have ever actually been impeached, compared to seventeen officials in other positions. Andrew Johnson was impeached on February 24, 1868, on charges of violating the Tenure of Office Act by removing Secretary of War Edwin Stanton from office. William ("Bill") Clinton was impeached on December 19, 1998, on charges of lying under oath to a federal grand jury and obstruction of justice. Both Johnson and Clinton were acquitted in the Senate. Impeachment proceedings against Richard Nixon had made it out of committee, but he resigned from office on August 9th, 1974 before it could be debated on the House floor.
Impeachment inquiries have been attempted on a number of presidents throughout the United States' history, including John Tyler, Harry Truman, and Ronald Reagan. In fact, every elected president since 1980 has been the subject of at least one Congressional resolution that suggested impeachment inquiries.