What precisely is Robert Mueller trying to do?

I'm still trying to wrap my brain around Robert Mueller's press conference yesterday.  He almost openly invited Congress to institute impeachment proceedings against President Trump, which is so far outside his terms of reference as a special counsel that it defies belief.

Mr. Mueller’s report outlined Mr. Trump’s myriad efforts to interfere with or shut down the special-counsel investigation but didn’t recommend charges, dodging the central questions of whether it amounted to a crime. “This report does not conclude that the president committed a crime, it also does not exonerate him,” the report found. Mr. Mueller on Wednesday emphasized this in his remarks, saying, “If we had had confidence that the president clearly did not commit a crime, we would have said so.”

Mr. Mueller said he was bound by departmental policy, which is based on two opinions from the Justice Department’s Office of Legal Counsel from 1973 and 2000 that concluded that a sitting president couldn’t be charged with a crime because it would unduly interfere with the constitutional responsibilities of the office. Under the Constitution, Congress can remove a president for alleged wrongdoing through the impeachment process. Criminal charges could then be brought after the president leaves office or is removed, the department concluded.

There's more at the link.

What I don't understand is Mr. Mueller's deliberate fudging of the issue of criminality.  As special counsel, he and his team were to establish whether or not there was sufficient evidence to bring charges against President Trump (ignoring, for the moment, the question of whether those charges would be brought while he was in office, or afterwards).  That was his sole mandate.  He did not have any mandate to decide whether the President was guilty or innocent - only whether or not there was sufficient evidence to warrant a trial.  The judge and jury would have then settled the question of guilt or innocence.  That's their job.  It's not a special counsel's job!

By speaking as he did, and choosing the words he did, Mr. Mueller essentially said that extra-judicial proceedings would be the best way forward - namely, impeachment proceedings in Congress.  It's as good as saying, "Well, I couldn't find a way to nail President Trump in court, but in my personal opinion he deserves to be nailed, so Congress, it's up to you."  That's so grossly unprofessional, so clearly biased and outside any possible parameters of his position, that I'm left shaking my head in disbelief.

I think this verifies beyond any possible doubt the existence of what President Trump has called "the swamp" in Washington D.C.  I think it has also verified beyond any possible doubt that Mr. Mueller is one of the major players in the swamp.

I foresee all sorts of difficulties ahead.  If the swamp can be this brazen, this open, about its determination to overturn the results of an election, and the will of the American people . . . then this Republic is in very real danger of being overthrown by its own bureaucrats.  There may be literally nothing that they're not willing to do to enforce their will over ours.  (For one fictional example, see Matthew Bracken's "What I Saw At The Coup".  Suddenly that no longer seems nearly so far-fetched as I once thought it was.)

That's a horrifying thought.  The question is, what are we, the people, prepared to do about it?  I suspect we're going to have to act, sooner or later.  We certainly can't trust our politicians to fix the problem on our behalf.

Peter