Washington — William Barr was sworn in as attorney general at the White House on Thursday evening. He was confirmed earlier in the day by the Republican-controlled Senate, despite Democrats' concerns that he may limit the scope of special counsel Robert Mueller's investigation into Russian meddling in U.S. elections.

William Barr is sworn in as attorney general by Chief Justice John Roberts. Official White House Photo by Tia Dufour

Although it was a near-party-line 54 to 45 vote, Democratic senators Doug Jones of Alabama; Kyrsten Sinema of Arizona; and Joe Manchin of West Virginia broke with their party and joined their Republican colleagues in voting in favor of Barr's nomination. GOP Sen. Rand Paul of Kentucky voted no, citing Barr's record on privacy and surveillance issues.

The White House and Republican leadership had urged senators to confirm Barr and allow him to take the helm of the Justice Department, which has been led on a temporary basis by acting attorney general Matthew Whitaker since then-attorney general Jeff Sessions was abruptly ousted in early November.

Barr's nomination had been approved by the Senate Judiciary Committee in a 12-10 vote along party lines last week.

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The longtime Republican lawyer will assume oversight of Mueller's far-reaching investigation, which is also probing possible coordination between Trump campaign associates and the Kremlin. Since the president announced Barr's nomination in early December, Democratic lawmakers have raised doubts about Barr's ability to remain neutral while overseeing the probe.

Barr, who led the Justice Department for a little over a year under President George H. W. Bush, wrote a memo to deputy attorney general Rod Rosenstein last year in which he argued the president should not be forced to submit to questioning by the special counsel. In the memo, Barr argued that "Mueller's obstruction theory is fatally misconceived" and based "on a novel and insupportable reading of the law."

During his confirmation hearing in January, he assured senators of his independence and said he would not be bullied by anyone into doing something he believes is wrong if he takes the helm of the Justice Department. Barr, however, did suggest he might not release Mueller's final report to the public, saying that in the event prosecution is declined, the findings may not be made public.

Barr also said he agreed with the longstanding Justice Department opinion that presidents can't be indicted while in office.