Howard Baker's question sliced to the core of Watergate: "What did the president know and when did he know it?"
Repeated over and again in the senator's mild Tennessee drawl, those words guided Americans through the tangle of Watergate characters and charges playing daily on TV to focus squarely on Richard Nixon and his role in the cover-up.
Baker's famous question has been dusted off for potential White House scandals big and small ever since.
Baker, later became Senate majority leader, chief of staff to President Ronald Reagan and one of the GOP's elder statesmen died Thursday at his Tennessee home of complications from a stroke suffered days earlier, according to an email distributed at the law firm where Baker was senior counsel. He was 88.