Bob Mueller has an unreleased Trump letter about firing James B. Comey. Here’s why that’s big.

https://www.washingtonpost.com/news/the-fix/wp/2017/09/01/bob-mueller-has-trumps-letter-explaining-why-he-fired-james-comey-heres-why-thats-big/?utm_term=.86e2a8f65717&wpisrc=nl_az_most&wpmk=1