Pulitzer Prize-winning Washington Post journalist Bob Woodward, whose dogged pursuit of the Watergate story was part of the journalistic and legal process that led to Nixon's resignation joins 'The Beat' for the first time on the eve of Bob Mueller's historic testimony. Woodward calls the Mueller hearing 'democracy' at work, and the report 'a very important presentation of findings about presidential behavior.' Woodward says Mueller didn’t find the 'evidence that we saw in Watergate' and not finding 'some sort of conspiracy' is 'very significant.' But, he adds, 'clearly' there was 'some sort of effort to strangle' the probe and reports there is 'a governing crisis' inside The Trump White House. In a fitting close to the interview, Woodward says 'let's keep digging.'