Article II Section 4 of the United States Constitution states "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."
Given the current legal definition of "bribery" in US law, ALL civil officers who have received directly, or indirectly, some type of economic or other benefit, from ANY entity other than the Compensation required by the US Constitution or private transaction completely irrelevant to their office or its benefits, are found guilty of accepting bribery and must be removed from office immediately.
It is clear what our foundling fathers were trying to achieve with Article II Section 4 of the United States Constitution.