An article in The New York Times, also published on May 22nd, gives a somewhat different impression. The Times' article provides a roadmap to impeachment indicating that Muller's role in the future of the presidency, while important, is in no way going to be determinative.
Both articles are worth reading. My comment relates to the use of the word "depends" in the headline from the email alert sent by The Post.
Our democracy, if it is to survive, can never "depend" on the actions of any government official (including the president, by the way). We are tempted, always, to hope that one person (whether it is President Obama, Robert Mueller, or someone else) can "solve" our problems for us. That approach assumes that we are the "governed," not the "governing." Hoping that someone else is going to extricate the nation from the nightmare of the Trump presidency - and the nightmare of our failed government - is an illusion. WE, not someone else, are going to have to organize, strategize, and act.
Waiting for Robert (or for anyone else), is just delaying the inevitable. The future of our democracy will require political action by ordinary Americans.
That means "us."