Nixon directed an operation that sought to subvert an election against his Democratic opponent during Watergate scandal that Woodward uncovered as a young reporter working for The Post.
There is evidence of impropriety among key staffers of the Trump campaign, yet Woodward cautioned journalists Thursday night to follow the story and evidence patiently.
When reporters fail to get out, report thoroughly and wait for a story to guide them, they are at risk for getting it wrong, Woodward said.
When former President Gerald Ford pardoned his predecessor, Woodward said it appeared at the time to represent a grave case of corruption.