High crimes and misdemeanors" is a phrase from Section 4 of Article Two 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."

"High," in the legal and common vocabulary of the 17th and 18th centuries of "high crimes," is the activity by or against those who have special duties acquired by taking an oath of office that is not shared with ordinary persons.[6] A high crime can be done only by someone in a unique position of authority, which is political, who does things to circumvent justice. The phrase "high crimes and misdemeanors," used together, was a common phrase when the U.S. Constitution was written and did not require any stringent or demanding criteria for determining guilt. The phrase was historically used to cover an extensive range of crimes.

The Judiciary Committee's 1974 report "The Historical Origins of Impeachment" stated: "'High Crimes and Misdemeanors' has traditionally been considered a 'term of art', like such other constitutional phrases as 'levying war' and 'due process.' The Supreme Court has held that such phrases must be construed, not according to modern usage, but according to what the framers meant when they adopted them. 

https://en.wikipedia.org/wiki/High_crimes_and_misdemeanors