Much rhetoric has been bandied about recently about presidential impeachment. (Fans of courtroom drama likely know that impeachment also can mean questioning a witness's veracity, but I digress.)
At its heart, impeachment is a constitutional process.
“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.” So says Article II, Section 4 of the U.S. Constitution. Article III, Section 2(3) defines treason as “consist[ing] only of levying war against [the United States] or in adhering to their enemies, giving them aid and comfort.” Article I, which delineates the powers and scope of the legislature, provides at Section 2(5), that the House of Representatives shall have the sole power of impeachment, and at Section 3(6) and (7) provides that the Senate has the sole power to try all impeachments; that the chief justice of the United State presides when the president is tried; that conviction must be by a two-thirds majority; and that judgment extends only to removal from, and disqualification to hold future, office.
To put the presidential impeachment process in the more familiar context of a trial: the House of Representatives acts like a grand jury, conducting an investigation and determining whether to bring articles of impeachment. The Senate tries the case and determines the outcome like a jury, with the chief justice presiding like a judge.
Little case law exists to flesh out these constitutional bones. Constitutional scholars like Alan Dershowitz and Laurence Tribe have written entire books on the subject, and tomes by lesser-known authors are flooding bookshelves. History provides few examples. Only two presidents, Andrew Johnson in 1868 and Bill Clinton in 1998, were actually impeached, and neither was convicted. Richard Nixon was not impeached - he resigned after the House of Representatives' judiciary committee authorized articles of impeachment against him. (Governor Hogan's father, Lawrence J. Hogan Sr., then the congressman from Maryland's fifth district, was the only Republican to vote for all three articles of impeachment, but again I digress.)
The House of Representatives has brought impeachment proceedings against only 19 people - including Johnson and Clinton - in 230 years, on charges ranging from bribery to perjury to favoritism in appointments. Of those 19, eight were found guilty, seven were acquitted, three resigned before trial, and the Senate expelled one, a senator, in 1797 before trial. Of the seven acquittals, one was Samuel Chase, one of Maryland's four signers of the Declaration of Independence and the only Supreme Court Justice to be impeached. Justice Chase's impeachment shows how what should be a constitutional process can become a political one. Jeffersonians, alarmed at how Federalist judges like Chase had claimed and used power through judicial review of legislation to determine constitutionality, sought to remove them for partisan reasons.
Much of the dispute surrounds the meaning of Article II's “high crimes and misdemeanors,” which remains undefined in the Constitution. Commentators have defined it as how the Framers would have in the context of prevailing English and American law in the 1780's, or even whatever George Washington would not have done. Then-representative Gerald Ford cynically quipped in 1970 during an investigation of Supreme Court Justice Douglas, “[a]n impeachable offense is whatever a majority of the House of Representatives considers it to be at a given moment in history.” We are unlikely to receive much official guidance from the Supreme Court because, in 1993 in U.S. vs. Nixon, an impeachment case unrelated to the former president, the Supreme Court determined that it lacks the power to review the Senate's impeachment proceedings.
Whatever one thinks about the process, one thing remains clear: impeachment, designed both to be a check on the president's power and a path for removal short of assassination when voting a president out, can be a divisive, yet powerful weapon not to be wielded lightly. Our integrity and unity as a nation hangs in the balance.