Trump insists tweeting about Stone case wasn't political intervention

President Donald Trump said on Wednesday he's "not concerned about anything" after the four federal prosecutors who recommended a sentence of seven to nine years for Roger Stone, a former Trump campaign adviser, resigned from the case in protest after the Justice Department said such a sentence "would not be appropriate."

The unusual intervention on Tuesday by the DOJ raised questions of political interference and came just hours after Trump tweeted that such a sentence for Stone was "horrible" and a "miscarriage of justice."

Trump on Wednesday insisted his tweet was not political interference and lashed out at the four prosecutors, who, he added, "should go back to school and learn."

"Nine years recommended by four people -- perhaps they were Mueller people -- I don't know prosecutors," Trump continued. "They hit the road pretty quickly."

The president also congratulated Attorney General Bill Barr in another tweet for "taking charge of the case." Barr, it was announced on Wednesday, has agreed to testify next month before the House Judiciary Committee.

Even though Trump remains adamant he played no role in the DOJ intervention on Tuesday, he's equally adamant doing so would have been fully within his rights.

South Carolina Sen. Lindsey Graham, one of the president's closest political allies, has publicly disagreed with Trump on the matter.

"I don't think the president should have tweeted about on ongoing case," Graham said Wednesday.

Stone was convicted in November on seven counts: five counts of lying to Congress, one count of witness tampering and one count of obstruction of a proceeding. The charges were levied by special counsel Robert Mueller as part of his investigation into Russian interference in the 2016 U.S. presidential election.

Trump declined to say whether he'd consider pardoning Stone.

"I don't want to talk about that now," Trump said.