Donald Trump is so ticked off at Robert Mueller that he's calling him an Obama guy.

The special counsel is actually a registered Republican.

The president's eruption on Twitter yesterday fueled all kinds of media chatter about whether Mueller, who seems to be in the final phases of his Russia investigation, is about to drop some major indictment.

Maybe the president is just worked up because, according to news accounts, he's spent the last several days with his lawyers, hammering out written answers to Mueller's questions. (Does this mean there won’t be a face-to-face interview? Who knows?)

What I'm hearing from the White House is that the president is simply sick of the long-running investigation and, after conferring with his lawyers, wants to bring it to a head.

Trump has made his "witch hunt" allegations for much of the Mueller probe.And by the way, it’s hardly unprecedented to try to investigate those who are investigating you. Bill Clinton and his allies mounted a sustained campaign to demonize Ken Starr.

But Trump's attacks yesterday may be his harshest yet.

"The inner workings of the Mueller investigation are a total mess," Trump tweeted. "They have found no collusion and have gone absolutely nuts. They are screaming and shouting at people, horribly threatening them to come up with the answers they want.

"They are a disgrace to our Nation and don't care how many lives the [sic] ruin. These are Angry People, including the highly conflicted Bob Mueller, who worked for Obama for 8 years. They won't even look at all of the bad acts and crimes on the other side. A TOTAL WITCH HUNT LIKE NO OTHER IN AMERICAN HISTORY!"

The all-caps was just for emphasis.

The president can certainly argue that Mueller, even with his charges against Paul Manafort, Rick Gates, Michael Flynn and others, has come up with no evidence of collusion with Russia.

But keep in mind that it was Trump's own appointee, Rod Rosenstein, who named Mueller as special counsel, and the deputy attorney general says he's doing a good job.

What's more, it was George W. Bush who tapped Mueller as FBI director. Obama just let him finish out his 10-year term, and tacked on an additional two years. So to suggest that Mueller is some kind of Obama loyalist is just wrong.

One aspect that the pundits are focusing on is that the latest attack on Mueller comes after the president replaced Jeff Sessions with Matt Whitaker, who has a history of criticizing the special counsel. But whether the acting attorney general will take any steps to curtail the probe remains to be seen.

By outward appearances, Mueller seems to be down to third-level players. The Wall Street Journal reports that he is investigating whether veteran GOP operative Roger Stone tried to intimidate a witness who is contradicting his insistence he had no pipeline to WikiLeaks on the hacked Democratic emails. In emails to his former friend, Randy Credico, the Journal says, Stone threatened to "sue the f---" out of him and called Credico "a loser a liar and a rat." But this is pretty small potatoes.

The president also weighed in on the press yesterday, as he is wont to do. I reported yesterday on a spate of stories (The Washington Post, L.A. Times, Politico) about how Trump has been angry, furious and lashing out since the midterms as he mulls another White House shakeup.

Insiders tell me that many of the leaks likely emanate from places such as the Homeland Security Department and National Security Council, where people's jobs are threatened (such as Kirstjen Nielsen and deputy NSC director Mira Ricardel, who's being transferred after Melania Trump called for her firing). The president often discusses job changes with advisers and doesn't mind the rumors that float around and hit the press.

Trump tweeted yesterday: "The White House is running very smoothly and the results for our Nation are obviously very good. We are the envy of the world. But anytime I even think about making changes, the FAKE NEWS MEDIA goes crazy, always seeking to make us look as bad as possible! Very dishonest!"

I mean, why would anyone think he's angry?

But the president does have a point that routine personnel moves after an election are getting the media’s "chaos" treatment — even if "running very smoothly" is not the most apt description of this White House.