When Attorney General William P. Barr testified before the House Judiciary Committee on Tuesday, Rep. Mary Gay Scanlon (D-Pa.) questioned him about an assertion that he had made in interviews echoing President Trump’s opposition to mail-in voting. “Foreign countries could manufacture counterfeit ballots,” Barr had said in the interviews. Scanlon asked Barr if he had evidence to support such a bold assertion. “No I don’t,” he responded. “But I have common sense.”

It was an extraordinary statement.

Traditionally, the Justice Department doesn’t make allegations or accusations based on “common sense.” Government lawyers — all lawyers — are required by courts to rely on facts and evidence, not conjecture. And yet here was the top law enforcement officer in the United States, the nation’s top lawyer, relying solely on subjective common sense to promote a highly politicized accusation. And it followed a pattern of deception, evasion and misrepresentation that by Barr’s own stated standards would have meant being fired, even disbarred, had one of his Justice Department lawyers behaved this way.

The stakes are enormous. On Thursday, Trump reiterated his frequent refrain that the use of mail-in ballots will make the 2020 presidential election “the most INACCURATE & FRAUDULENT Election in history.” The president’s transparent effort to sow doubt — without any factual support — in an election that he is desperate not to lose, now has a willing accomplice in the attorney general of the United States. Yet it gets worse. Barr’s “common sense” belief is directly contrary to the facts: According to a report from the MIT Election Data and Science Lab, which was submitted into the record at Barr’s hearing, of the more than 250 million ballots that have been cast by mail during the past 20 years, approximately 143 were found to be fraudulent — that is, a fraud rate of less than 0.00006 percent.

This was not the only example of Barr’s misrepresenting the facts to support the president’s baseless assertions during his testimony. In another instance, he shockingly repeated the discredited allegation by the president and his fringe allies that the so-called Steele dossier predicated the Russia investigation, notwithstanding findings by former special counsel Robert S. Mueller III and his own department’s inspector general to the contrary. “Maybe if they vetted the dossier, we wouldn’t have the whole Russiagate problem,” Barr said.

The statements in Barr’s testimony on Tuesday cannot be viewed in a vacuum. He has made misleading — even outright false — statements throughout his tenure as attorney general. In March, a federal judge found that Barr exhibited a “lack of candor” in releasing the Mueller Report to the public; the judge said Barr had “distorted the findings” and falsely created a “one-sided narrative” in a “calculated attempt to influence public discourse” in favor of President Trump.

And then there was Barr’s unusual removal of Geoffrey Berman from his post as the U.S. attorney for the Southern District of New York. That effort began with a clear lie from Barr — that Berman had “stepped down” when in fact he had not — and Barr’s subsequent explanation did not improve his credibility. His proffered rationale that he wanted to appoint Jay Clayton, the chairman of the Securities and Exchange Commission, to the position does not justify the abrupt termination of Berman, because Clayton could not have assumed the position without being confirmed, a process likely to take months. Barr offered no other logical explanation in his testimony on Tuesday.

Barr’s lack of credibility leads to the inevitable conclusion that he is acting in bad faith and puts a sharp microscope on his efforts to bolster the president’s false and vengeful theories. It also colors Barr’s decisions to initiate three separate investigations of Obama-era officials and investigations; to intervene in the prosecutions of Roger Stone and Michael Flynn, the president’s allies; and to decline investigations into the president based on his effort to extort a foreign country into assisting his reelection effort and his commutation of Stone to silence him.

Contrary to the bedrock principles of the independence of the Justice Department, Barr’s bad faith conduct always personally and politically benefits Trump.

So when Barr testified on Tuesday that “I think antifa is involved in Portland” — again offering only conjecture and not facts — the American public cannot take his word for it without any supporting proof. And when he repeatedly raises baseless concerns about voter fraud undermining mail-in balloting, he undermines our elections rather than protects them.

At bottom, if the American public cannot trust the attorney general, it cannot trust the fairness of our system of justice.

I spent 10 years in the Justice Department proudly representing the United States in federal court as a prosecutor. If I had ever told a judge that my allegations were not based on evidence but instead on my own “common sense,” or what “I think,” I would have been thrown out of the courtroom. If I had ever made an argument that blatantly misrepresented the facts or the law, as Barr has repeatedly done, I likely would have been sanctioned. And if a federal judge ever made a determination that I “lacked candor,” the department’s Office of Professional Responsibility would have initiated an investigation that likely would have resulted in serious professional consequences.

“Mr. Attorney General,” Rep. Ben Cline (R-Va.) asked him Tuesday, “what would the consequences be to your Justice Department lawyers if they doctored underlying documents so they could support evidence submitted to a federal court?”

“In the abstract, talking generally,” Barr answered, “that lawyer would be fired.”

The attorney general has moved far beyond abstractions. By his own standard, Barr would fire any other department lawyer who engaged in his conduct. Both common sense and factual evidence would demand it.