‘Barrking’ at Don, even before he’s confirmed

William Barr says he’d stand up to the President.

The attorney general wannabe said Tuesday that Robert Mueller is not on a political witch hunt and warned that it would be a blatant “abuse of power” for President Trump to interfere in any way with the special counsel’s investigation.

Barr (photo), who was picked by Trump to replace Jeff Sessions, fired several indirect shots at the President during his first confirmation hearing before the Senate Judiciary Committee and vowed the law — not the commander-in-chief — would serve as his guide.

“I don’t believe Mr. Mueller would be involved in a witch hunt,” Barr, who previously served as AG in the first Bush administration, replied when asked about the President’s favorite insult against Mueller, who’s investigating whether Trump or his campaign participated in Russia’s attack on the 2016 election.

Barr, 68, said it would be a “breach” of “constitutional duty” for Trump to meddle in an investigation he has “a personal stake in” — including the special counsel inquiry. Barr said, “That would be a crime,” when asked of a theoretical situation in which Trump offers the promise of a pardon to anyone who refuses to cooperate with Mueller. Barr said he would resign if ordered by Trump to do something illegal and said he wouldn’t carry out an order to fire Mueller for anything but “good cause.”

Sen. Dianne Feinstein zeroed in on a June memo Barr sent to Justice Department brass that blasted as “fatally misconceived” Mueller’s separate inquiry into whether Trump at any point obstructed justice.

Feinstein said the memo showed a “determined effort” to “undermine” Mueller as it argues Trump couldn’t have obstructed justice by firing FBI Director James Comey because it was within his purview. Barr said the memo sought to advise against “stretching a statute.”