Trump has also repeatedly complained publicly and privately over Sessions' decision to recuse himself from the federal investigation into possible collusion between the Trump campaign and Russian Federation because he'd worked on Trump's campaign.
In a Labor Day tweet, President Donald Trump criticized Attorney General Jeff Sessions for the recent investigations and indictments of two republican Congressmen, one of them being local Rep. Chris Collins (R-Clarence).
Mr Trump wrote on Twitter that the justice department's decision to file charges put "easy wins now in doubt".
Chris Collins of NY was indicted on insider trading charges, which he has denied, while Duncan Hunter of California was accused with his wife of using campaign donations for personal purposes. The White House did not immediately react.
"This tweet alone may be an impeachable offense", Toobin stated.
Last week, Trump told Bloomberg the attorney general was safe in his job until November but declined to say if he would keep Sessions in the role beyond then.
Later in the segment, Napolitano said that such tweets could be used by Mueller to potentially prove corrupt intent in an obstruction of justice charge.
In a second tweet, Trump said Democrats "must love" Sessions and likened the situation to Democrats support for former FBI Director James Comey, whom Trump fired previous year.
Appearing to express dismay on Monday at the investigations which brought about charges against two of his most loyal supporters in Congress, Reps.
The Fox analyst said it seemed inappropriate for Trump to weigh in and say the DOJ should not be investigating his congressional allies because it could hurt the party in the midterm elections.
Also under investigation is Trump's conduct in dismissing Comey, particularly why he fired him and whether he pressured him to be generous to Michael Flynn, the president's former national security adviser. Trump did not have any public events Monday.
He later added, "The sentiment at the core of that tweet is so contrary to the mission of the Department of Justice, and it's such an insult to the decent people who work there". Both have pleaded not guilty.
While Trump suggested the investigations into the two lawmakers began during the Obama administration, the charges against Collins stem from actions he allegedly took a year ago - including calls he placed while at the White House for a congressional picnic hosted by Trump.