Jeff Sessions also reportedly explored the idea with members of Congress but ultimately chose not to pursue an investigation.
On several occasions, President Trump raised the idea of prosecuting Hillary Clinton, which he had repeatedly pledged on the campaign to do once in the White House.
Trump raised the subject with Deputy Attorney General Rod Rosenstein and Matt Whitaker, who was then-chief of staff to Jeff Sessions, according to CNN. "President also wanted his previous White House counsel, Don McGahn, to ask the Justice Department to prosecute Clinton on numerous occasions, but McGahn rebuffed doing that," CNN said.
The New York Times reported that Trump raised the notion last spring, asking questions about prosecuting Clinton and also former FBI Director James Comey.
McGahn reportedly "rebuffed the president, saying that he had no authority to order a prosecution. Mr. McGahn said that while he could request an investigation, that too could prompt accusations of abuse of power. To underscore his point, Mr. McGahn had White House lawyers write a memo for Mr. Trump warning that if he asked law enforcement to investigate his rivals, he could face a range of consequences, including possible impeachment," the Times reported.