As Sen. Martha McSally (R-Ariz.) walked through the hallways of the Senate Thursday, CNN senior congressional correspondent Manu Raju asked her if the Senate should consider “new evidence as part of the impeachment trial.” McSally shot back: “Manu, you’re a liberal hack. I’m not talking to you.”

“You’re not going to comment about this?” a dazed Raju asked. “You’re a liberal hack, buddy,” McSally replied as she walked away. Predictably, conservatives cheered, while mainstream media decried McSally’s move as unbecoming.

Whatever your take, the interaction reflects three years of mounting frustration with an overtly partisan media, exemplified by CNN, which has dropped any pretense of fairness and become an organ of the Democratic Party.

The problem isn’t that Raju asked the question — that’s his job, after all. It’s that virtually all questions posed by political reporters these days are framed to support the narratives and assumptions of one political party, the Democrats.

CNN’s Jake Tapper, remarking on the incident, called Raju’s query reasonable, because it was “the question of the day.” Indeed, that’s the problem. Democrats are always dictating the “question of the day.”

As Tapper surely knows, there is no Lev Parnas “evidence” about ­alleged Trump-Giuliani misdeeds in Ukraine. There are only allegations from a sordid character named Lev Parnas. Now, perhaps those allegations will be proved true. But any honest observer of Washington understands that Democrats are stringing out these investigations until the election.

By referring to Parnas’ handwritten notes as “evidence,” Raju is merely perpetuating a talking point. Which would be fine, of course, if reporters were also stalking the hallways of the Senate demanding to know if Democrats were prepared to investigate new “evidence” of alleged wrongdoing by Hunter Biden.

On the whole, mainstream outlets have exhibited deep skepticism about verified and unverified accusations about the vice-presidential son’s Burisma shenanigans. They should do the same in the Parnas case, as well (Tapper, to his credit, has raised some questions).

You’d think that journalists who had recently subjected the nation to a hysterical three-year carousel of botched Russia “collusion” stories, fed to them by partisans, would show a lot more caution, rather than blindly embracing the theories of House Democrats.

In 2017, Raju reported an “exclusive” that Donald Trump Jr. had advance notice of WikiLeaks dumps against the Democratic Party, thus proving criminal conspiracy. It turned out Raju had gotten the date on a supposedly incriminating e-mail wrong: The e-mail apprised Don Jr. of documents that were ­already in the public record.

CNN ran a massively embarrassing correction while insisting the reporter had followed “editorial process.” But Raju never explained how his two supposedly independent sources both got the date on the e-mail wrong.

The Don Jr. e-mail story was just one of dozens of failed scoops that fueled paranoia around the 2016 election results. CNN was perhaps the worst offender, so it really has no business feigning indignation when a Republican senator calls one of its reporters a “hack.”

You only need to juxtapose the McSally brouhaha with Nancy ­Pelosi’s news conference this week to see how liberal journalistic malpractice works. Without any evidence, the House speaker accused Team Trump of sedition and criminality and claimed — again — that the 2016 presidential election had been stolen by Russians, knowing full well no one would really challenge her.

What’s most infuriating about CNN isn’t that hosts like Don Lemon and Chris Cuomo or ­reporters like Raju, Jim Acosta and Jim Sciutto have an agenda — it’s that they pretend they don’t.

Was it a good moment for McSally, who is serving her first term in the Senate after being appointed to take the late John McCain’s seat? Probably not. Losing your cool is rarely a good look for a politician, and independent and moderate voters who will decide her fate are unlikely to understand the context of her frustration.

But that doesn’t render her grievance illegitimate.

Twitter: @DavidHarsanyi