When the January 6 House select committee announced Monday that it would be holding an emergency hearing the following day with a surprise witness, John Dean sounded a note of warning. Dean, the former White House counsel who pleaded guilty to obstruction of justice during the Watergate scandal, noted there had only been one surprise witness during the Watergate hearings: Nixon aide Alex Butterfield, who revealed the existence of the secret taping system in the Oval Office.

(SOURCE) https://www.cnn.com/2022/06/29/opinions/jan-6-cassidy-hutchinson-worse-than-watergate-hemmer/index.html