turning point. n. 1. a moment when the course of events is changed: the turning point of his career. 2. a point at which there is a change in direction or motion. 3. (Mathematics) maths a stationary point at which the first derivative of a function changes sign, so that typically its graph does not cross a horizontal tangent.
Because high Crimes and Misdemeanors was a term of art used in English impeachments, a plausible reading supported by many scholars is that the grounds for impeachment can be not only the defined crimes of treason and bribery, but also other criminal or even noncriminal behavior amounting to a serious dereliction of duty.
On December 3, 2013, the House Judiciary committee held a hearing on the President that was formally titled The President's Constitutional Duty to Faithfully Execute the Laws, which has been viewed as an attempt to begin justifying impeachment proceedings.