Of all the challenges Robert Mueller faced in his investigation, the toughest one was the decision he had to make on obstruction of justice. Despite the critics, he made it well.

In contrast with the topic of conspiracy with Russian interests, this was always the subject that put President Trump himself at risk. This was why Mueller was appointed in the first place — because the investigation involved the president, and the top brass of the Justice Department was situationally compromised, thus necessitating a special counsel.