Democrats on the Senate Judiciary Committee – some of them candidates for their party’s presidential nomination and hungry for TV exposure – battered Attorney General William Barr Wednesday with hostile and often insulting questions when he testified about his handling of the report by Special Counsel Robert Mueller.

But Barr remained unflappable in his testimony about the Mueller report, which looked at Russian interference in our last presidential election and allegations that President Trump obstructed the Mueller probe.

At the end of the day, Barr emerged unscathed from the Democratic assault. And the Democratic would-be presidents had their video clips for future campaign commercials, showing how tough they could be in battling the Trump administration.

Barr was scheduled to testify in front of the House Judiciary Committee on Thursday about the Mueller report, but late Wednesday the Justice Department told Chairman Jerrold Nadler, D-N.Y., that the attorney general would not be appearing due to Nadler’s insistence that committee attorneys question Barr.

Barr quite properly said he should be questioned by committee members – not their attorneys.

Nadler threatened to hold Barr in contempt. But Georgia Rep. Doug Collins, the ranking Republican on the House Judiciary Committee, said that Nadler’s unusual maneuver was in reality intended to “torpedo our hearing.”

Nadler isn’t running for president, but clearly enjoys being the center of attention when the TV cameras are turned on.

Much of the questioning in the Senate centered on a March 27 letter from Mueller to Barr that was apparently leaked to the media the night before Barr’s appearance.

In the letter, Mueller complained that Barr’s March 24 letter to Congress summarizing the conclusions of the special counsel’s report “did not fully capture the context, nature, and substance” of Mueller’s report.

That Mueller would write such a letter is, in context, rather odd. After all, Barr had offered to let him review the attorney general’s March 24 letter before he sent it to Congress, but Mueller declined.

Importantly, nowhere in his letter did Mueller say that Barr’s letter was inaccurate. Barr actually called Mueller after receiving the letter and asked if he was claiming that Barr’s summary was inaccurate. Mueller said he was not making that claim; rather, his beef was that the media were misinterpreting the special counsel’s investigation.

Responding to an antagonistic question from Sen. Dick Durbin, D-Ill., Barr said his short letter to Congress never attempted to capture the entire Mueller report; he was just giving lawmakers the “final verdict.”

And former federal prosecutor Andrew McCarthy noted in a Fox News op-ed that Mueller’s complaint about the “context” of the report is a “microcosm of Mueller’s collusion probe: sound and fury, signifying nothing; an investigative process predicated on no criminal conduct.”

“Context” is not a prosecutor’s job McCarthy wrote, because “that is the stuff of political narratives.”

As Barr said in his testimony, when a “prosecutor has exhausted his investigation into the facts of a case, he or she faces a binary choice: either to commence or to decline prosecution.”

Mueller made that binary choice on the claim that Trump or his presidential campaign colluded with Russia to help Trump win the presidential election.

After 22 months of investigating, Mueller found that neither Trump nor any member of his campaign conspired or coordinated with Russia to put Trump in the Oval Office. In other words, Trump’s oft-repeated claims of “no collusion” were true.

But Mueller failed to reach a conclusion regarding obstruction of justice allegations against Trump. In an implicit criticism of Mueller, Barr said that if a “prosecutor isn’t going to make a decision, he shouldn’t investigate” a case.

All of this criticism of Barr over the Mueller letter is a tempest in a teapot. Almost the entire Mueller report is public. According to Barr, “just 8 percent of the public report was redacted” and “less than 2 percent has been withheld in the minimally redacted version made available to congressional leaders.”

In fact, while Barr laid out the categories of information that would have to be redacted, neither he nor Deputy Attorney General Rod Rosenstein was involved in the actual redaction. Those decisions were all made by Justice Department lawyers working with Mueller.

In any event, complaints about Mueller’s letter are like complaints about a movie trailer or a book review when the entire movie or the book have already been released. As Barr said, the report speaks for itself.

When asked about all of the news leaks that have occurred from the Justice Department, including those from inside the FBI that were noted by the Justice Department’s inspector general in his report on the Hillary Clinton email investigation, Barr told the Judiciary Committee that there are “multiple criminal leak investigations going on.”

That is good news, since leaks about ongoing investigations – whether they come from the FBI, the Justice Department, or the Office of the Special Counsel – are shockingly unethical and unprofessional behavior. They must not be tolerated.

Sen. John Cornyn, R-Texas, raised an important question that has puzzled many: If the FBI had evidence that Russian agents were trying to infiltrate or influence the Trump campaign, why didn’t the agency immediately brief the campaign to warn it about the problem?

The question matters because of suspicions about the potential political basis for this entire Mueller investigation.

Barr said he couldn’t “fathom why it didn’t happen.”

The attorney general confirmed that a team of Justice Department lawyers is investigating the circumstances (and legitimacy) of the decision by the FBI and the Justice Department to open a counterintelligence operation against the Trump campaign in 2016. This is an issue that Mueller essentially ignored in his 448-page report.

Barr made no apologies for his handling of the Mueller report, despite repeated attempts by Democrats to besmirch his professionalism and ethics.

That included Sen. Mazie Hirono, D-Hawaii, who told Barr she disagreed with his analysis of the law on obstruction of justice.

On that point, should the public trust the judgment of a partisan senator with no prosecutorial experience? Or should the American people trust an attorney general who is in his second go-round as the nation’s chief law enforcement officer, and who has held multiple prior posts inside the Justice Department?

The answer is obvious.

The dispute between House Democrats and the Justice Department has scuttled the House Judiciary Committee hearing planned for Thursday. But as Rep. Collins correctly observed, Barr gave “clear, informative testimony in the Senate.”

Collins blamed House Democrats for “rejecting the chance to question” Barr or “read the materials he has provided.”

Even if Barr does eventually testify before the House Judiciary Committee, don’t expect any ground-shaking surprises. We’ll probably just see a rerun of the Senate Judiciary Committee hearing, with another set of angry Democrats trying to outdo each other with their telegenic expressions of outrage at a Trump Cabinet member.