If we assume, for argument’s sake, that the special counsel has wanted to make a criminal case on the president (I’ve never been fully convinced of this), the challenge Mueller has had from the start is that there was no underlying crime to predicate his investigation. He was rashly appointed by Deputy Attorney General Rod Rosenstein in the uproar over the president’s ham-fisted firing of FBI director James Comey. But terminating executive-branch officers is not obstruction; it is a prerogative of the presidency. If it is done abusively or for unsavory motives, that could be grounds for impeachment, but not for criminal prosecution.
Ditto harassing the attorney general, contemplating the removal of the special counsel himself, and allegedly weighing in on whether Michael Flynn, the former national-security adviser, should be investigated. We can all agree — or, at least, many of us do agree — that it would be better if the president did not do such things. It should be indisputable, though, that the Constitution endows him with the authority to do them. If you don’t like it, vote him out of office . . . but it is not the business of prosecutors.