Valid grounds for impeachment are treason, bribery, or "high crimes and misdemeanors". The last of those three is not entirely well defined, but it's meant to cover acts that might not be criminal offenses as such if committed by an ordinary citizen, but constitute a breach of trust or abuse of power from a high ranking government official with special powers and special obligations. In military courts, such acts include perjury, abuse of authority, intimidation, misuse of assets, failure to supervise, dereliction of duty, unbecoming conduct, and refusal to obey a lawful order, and that definition can reasonably be applied to presidential "high crimes" as well.
An interesting fact about perjury is that it is usually taken to mean "lying under an oath of truth", but when the Constitution was written, it had the wider meaning of violation of any oath. The president and all members of cabinet, in fact any person taking a government job in the US, are sworn in by taking an oath of office, and can reasonably be considered under oath at all times. This means that lying in public about a substantial matter with the purpose of misleading, while holding any position of office for the US government, can be considered perjury.
To initiate the process of impeachment, the House of Representatives is required to first ask the Judiciary Committe to investigate whether such grounds exist, and a majority of the committee needs to decide to proceed with the matter. Formal impeachment then requires a majority vote in the House.
If a majority of the House votes for impeachment, it falls to the Senate to conduct a trial, first considering arguments and evidence from both sides and listening to the witnesses each side chooses to call, and then passing judgment. Conviction requires a two-thirds majority vote by the Senate. If considered guilty, the impeached person is immediately removed from office, while acquittal allows the person to remain. In addition to removal from office, Senate may extend the judgment to include disqualification, which bars the convicted person from holding any future government office.
Only two US presidents have ever been impeached (Andrew Johnson in 1868 and Bill Clinton in 1998), and both were acquitted by the Senate. Richard Nixon was heading for impeachment in 1974, but resigned before any impeachment vote was held. For both Nixon and Clinton, the "high crime" was lying in public. Nixon lied to cover up illegal wire taps against his political opponents, and Clinton lied to cover up a sexual relation with a White House intern.
President* Trump lies all the time, about matters great and small, seemingly without any qualms or hesitation, and without remorse or repentance when he is caught and called out for it. That is not normal, and it constitutes a violation of his solemn oath to "well and faithfully discharge the duties of the office".
Will we finally see this section of the Constitution being applied successfully? There appears to be some reasons already. Feel free to use the checklist below as the Trump scandal unfolds.
- Treason
- Bribery
- Perjury
- Abuse of authority
- Intimidation
- Misuse of assets
- Failure to supervise
- Dereliction of duty
- Unbecoming conduct
- Refusal to obey a lawful order
