He says the inquiry is a "witch hunt".
He added: "These are Angry People, including the highly conflicted Bob Mueller, who worked for Obama for 8 years". In a separate tweet, he slammed what he called social media's unfavorable coverage of his administration and the Republicans.
"Check out how biased Facebook, Google and Twitter are in favour of the Democrats", he wrote.
Trump's full-throated denunciation of Mueller comes amid reports that he's about to hand down another indictment to a man connected to Trump associate Roger Stone, Jerome Corsi, who was recently D.C. bureau chief of Alex Jones' conspiracy site Infowars.
However, The Atlantic suggested that Trump's "specific" attacks on Mueller show that he is anxious about the outcome of the investigation.
Boot said of Trump, "His henchman has just been appointed acting attorney general, and even though he has not shut down the Mueller investigation, the odds are that Whitaker has access to Mueller's files". There is the feeling in Washington of an impending storm, of threats to the presidency from the outside and within.
Israeli coalition on brink after 'capitulation' in Gaza
The ruling coalition still holds a slender majority of 651 to 59 in the Knesset (Israeli Parliament) after Beiteinu's departure. We will dictate the time and circumstances that are right for Israel and are right for the security of our people.
While the president has been a frequent critic of the Mueller probe, his November 15 statements are the first since asking Attorney General Jeff Sessions to resign and designating Sessions's chief of staff, Matt Whitaker, as the acting attorney general.
"I thought (Rubio) was someone who was more principled and Reaganesque and would speak up for American democracy", Boot asserted.
They note that "there's already a statute that lays out what should happen when the attorney general's position becomes vacant: the Justice Department's own succession law", which would place deputy attorney general Rod Rosenstein as "next in line" following Jeff Sessions' ousting.
What is behind the Russian Federation investigation? "But anytime I even think about making changes, the FAKE NEWS MEDIA goes insane, always seeking to make us look as bad as possible".
Trump's latest attacks come as he and his lawyers put the finishing touches on their answers to a set of written questions from Mueller.
It has been established that senior members of Mr Trump's team met Russian officials, while several of these meetings were not initially disclosed.
US President Donald Trump lashed out on Twitter once again over the investigation. They must continue, even if they implicate persons or institutions connected to the President, to his campaign, or to his businesses.