Last week, in an all too typical rant, President Donald Trump told reporters that the investigation of possible collusion between his campaign and Russia was an “illegal investigation,” “treason” and an “attempted coup.” He expressed satisfaction that Attorney General William Barr was “going back to the origins of exactly where this all started. Because this was an illegal witch hunt and everybody knew it.”

Trump was able to portray Barr as his ally in exposing a “witch hunt” because the attorney general had told a House subcommittee that he was “reviewing the conduct” of the Russia investigation. Never mind that, as Barr acknowledged, Michael Horowitz, the Justice Department’s respected inspector general, has already been investigating the investigation, with a particular focus on whether there were improprieties in the way the FBI obtained a warrant to conduct surveillance of Carter Page, a former Trump campaign adviser with connections to Russia.

Barr’s decision to conduct his own inquiry into the origins of the Russia investigation is at best premature. At worst it is partisan and unprofessional, transparent pandering to the president who appointed him and the congressional Republicans who have endlessly agitated to discredit the Russia investigation.

Barr reinforced the latter impression when he told the Senate Appropriations Committee that “spying did occur” during FBI scrutiny of people associated with the Trump campaign. This echoed another Trump theme: that his campaign was spied on for political reasons.

To be fair, Barr added that “I am not saying that improper surveillance occurred. I am saying I am concerned about it, and I am looking into it. That is all.” Yet Barr is smart enough to realize that his reference to “spying” would be interpreted as an endorsement of Trump’s conspiracy theories about a partisan witch hunt.