Washington CNN  — 

Sen. Kamala Harris sent a letter to the Justice Department’s inspector general on Friday, requesting an investigation into whether Attorney General William Barr has acted upon requests or suggestions from President Donald Trump or other White House officials to investigate the President’s “perceived enemies.”

In a letter addressed to Department of Justice Inspector General Michael E. Horowitz, the Democratic presidential candidate cites the findings in special counsel Robert Mueller’s report and Barr’s Wednesday congressional testimony as the reasons for her letter.

“Such inappropriate requests by the President have been well documented,” Harris wrote. “Special Counsel Mueller … documented a disturbing pattern of behavior on the part of the President – repeated attempts to target his perceived opponents.”

“There must be no doubt that the Department of Justice and its leadership stand apart from partisan politics, and resist improper attempts to use the power of federal law enforcement to settle personal scores,” the letter reads.

Harris’ letter comes days after a heated exchange between the California Democrat and the attorney general, in which Barr parsed words to answer Harris’ question about whether the White House has “asked or suggested” that he open an investigation into anyone.

“I’m trying to grapple with the word ‘suggest,’” Barr said Wednesday at the hearing. “I mean, there have been discussions of, of matters out there that, uh – they have not asked me to open an investigation, but…”

Harris interjected: “Perhaps they’ve suggested?”

“I don’t know, I wouldn’t say suggest…” Barr said.

“Hinted?” Harris pressed.

“I don’t know,” Barr answered.

In her letter, Harris also points to details in Mueller’s report where he notes three occasions on which the President called for an investigation into Hillary Clinton.

Harris hasn’t been the only lawmaker to follow up on Barr’s testimony, which grew more tense following the revelation that Mueller reached out to Barr to express misgivings about his four-page letter. House Democratic Reps. Ted Lieu of California and Kathleen Rice of New York are asking the state bars in Virginia and Washington, DC, to begin ethics investigations into Barr following his recent congressional testimony.

In a letter to the DC and Virginia bars, Lieu and Rice charge that, in light of Mueller’s March 27 letter to the attorney general, Barr “at best misled Congress and at worst perjured himself” when he testified in mid-April – prior to the release of the Mueller report – that he did not know what was behind reports that members of Mueller’s team were frustrated.

Rep. Jerrold Nadler, the chairman of the House Judiciary Committee, has also persisted in his requests for the full unredacted Mueller report. Nadler on Friday threatened to hold Barr in contempt of Congress.

Also on Friday, Republican Sen. Lindsey Graham, the chairman of the Senate Judiciary Committee, sent a letter to Mueller asking whether he felt Barr misrepresented their phone conversation in his Senate testimony this week.

CNN’s Manu Raju contributed to this report.