If Donald Trump thinks he's getting a rough time from the journalist who cover him at the White House, he's never met Sam Donaldson. 

From 1977 to 1989 -- the Jimmy Carter and Ronald Reagan years -- Donaldson was was Chief White House correspondent for ABC News.  

During those twelve years, Donaldson proved to be a relentless, aggressive reporter, never letting the president get away with a vague, evasive, or unsatisfactory answer to a question.