President Trump said Thursday that a special counsel was not needed to investigate Russian interference in the 2016 election and asserted unprecedented bias among the lawyers conducting what he termed a “Witch Hunt Hoax.”

The president’s grievances, aired in a series of early morning tweets, represented the latest attempt by Trump and his lawyers to cast doubt on the work of the team of special counsel Robert S. Mueller III.

In one tweet, Trump quoted Alan Dershowitz, a professor emeritus at Harvard Law School, asserting that Mueller’s work could have been done by the Justice Department rather than “a multimillion dollar group of people with a target on someone’s back.”

“So true!” Trump wrote in his own voice.

Deputy Attorney General Rod J. Rosenstein appointed Mueller in May 2017 to lead the investigation, which is also examining whether Trump’s campaign coordinated with Russia during the election and whether Trump has obstructed the probe.

Rosenstein made the appointment after Attorney General Jeff Sessions recused himself from the investigation, a development that Trump has repeatedly criticized. In a tweet last week, Trump called the appointment of a special counsel “unconstitutional,” without providing elaboration.

In another tweet Thursday, Trump again referred to Mueller’s team as “13 Angry Democrats” and said there “has never been a group of people on a case so biased or conflicted.”

In fact, there are 17 staff members in Mueller’s office. Thirteen are registered Democrats, and four are unaffiliated or their affiliation is unknown, The Washington Post has reported. Mueller himself is a registered Republican, as is Rosenstein, a Trump appointee who is overseeing the investigation.

Trump also asserted Thursday that the continuing investigation is “a Democrat Excuse for LOSING the Election” and he asked “Where is the server?” — a reference to the personal email server Hillary Clinton used while secretary of state.

Trump in the past has argued that the Justice Department has been far more aggressive in investigating him than it was in investigation Clinton, his 2016 Democratic opponent.

In an earlier tweet on Thursday, Trump said he found it “ironic” that he was getting ready to make important trips to Canada and Singapore while “back home we still have the 13 Angry Democrats pushing the Witch Hunt!”

In another tweet on Thursday, Trump sent well wishes to Alice Marie Johnson, a woman whose life sentence for nonviolent drug offenses he commuted on Wednesday.

“Good luck to Alice Johnson. Have a wonderful life!” Trump wrote.