America’s political class is decadent and depraved, but our media class is arguably worse. The #MeToo exposure of big-name sexual predators like former NBC Today show host Matt Lauer confirmed what conservative critics had long asserted: that the liberal media’s pretensions of moral superiority were a sham. And the role played by the journalistic establishment in disgraced Democrat Rep. Katie Hill’s scandal adds further evidence that much of the press corps has become exactly what President Trump says: “Fake news … the enemy of the people.”

If political journalists had been doing their job, Ms. Hill might never have been elected to Congress in the first place. But the media’s enthusiasm to help Democrats win a House majority in last year’s midterm election was such that reporters didn’t produce journalism about Ms. Hill; instead they produced publicity. Coverage of Ms. Hill’s 2018 congressional campaign in various national media amounted to a massive contribution-in-kind of free advertising. Three weeks before the June 5 primary, for example, HBO aired a half-hour segment produced by Vice News entitled “Katie Hill’s Most Millennial Campaign Ever.” That in-depth coverage almost certainly helped boost the political newcomer’s profile, enabling her to edge Democrat rival Bryan Caforio in the primary. She then got more gushy publicity from such outlets as the New Yorker (“Katie Hill Is a New Kind of California Democrat. Can She Help Flip the House?”) and NBC (“Bisexual candidate Katie Hill hopes to be part of Democrats’ ‘blue wave’ ”).

Nowhere in that blitz of free campaign publicity did these allegedly professional reporters show any interest in whether Ms. Hill’s oft-proclaimed “bisexuality” might prove problematic. Now that the allegation of an affair with one of her congressional staffers has forced Ms. Hill to resign from the House, the same media that helped her get elected have decided to blame the journalist who exposed the Democrat’s unethical conduct.

Jennifer Van Laar is deputy managing editor for the conservative site Red State, and it was her October 18 report, involving evidence relevant to Ms. Hill’s divorce from Kenny Heslep, that detailed the first-term congresswoman’s sordid behavior. Ms. Van Laar has been accused by various voices in the left-leaning media of violating laws against so-called “revenge porn.” Yet it was not Ms. Van Laar or Red State, but rather the London Daily Mail, that published the most shocking photos of Ms. Hill’s behavior (e.g., smoking a bong in the nude). And as Ms. Van Laar wrote in that first story, she had also been “provided with intimate photographs” of Ms. Hill and a young female campaign aide that Red State had “chosen not to publish.” What was ultimately most damaging to Ms. Hill was not the revelation that her marriage to Heslep had involved a three-way arrangement with Morgan Desjardins, but rather that Ms. Hill dumped both her husband and her ex-girlfriend in early 2019 to pursue a sexual relationship with Graham Kelly, who served on her House staff as legislative director.

Allegedly, I hasten to add. Ms. Hill denied being intimate with Kelly, which would constitute a violation of House ethics rules, and, unlike the congresswoman’s involvement with Ms. Desjardins, we have not yet seen photographic proof of the alleged Hill–Kelly affair. The same establishment journalists who failed to vet Ms. Hill when she was “a rising Democratic star,” as the Associated Press called her, have continued failing in the wake of her resignation announcement. That left it to talk radio host Joe Messina to report that, according to his D.C. sources, House Speaker Nancy Pelosi had demanded Ms. Hill’s resignation after a preliminary inquiry confirmed the first-term congresswoman was sexually involved with the staffer. “My understanding is that a couple of [Ms. Hill’s other congressional] staffers … had proof that she was having an affair with one of her staffers. The Ethics Committee found out hard and fast that she did have that relationship,” Messina told his radio audience Monday.

One might imagine reporters on Capitol Hill would be eager to follow up on this, but no — instead of working to learn the details behind the congresswoman’s resignation, the press corps turned on Ms. Van Laar, whose Red State article had first exposed what Ms. Pelosi delicately called “errors in judgment” by Ms. Hill.

On CNN, for example, feminist author Jill Filipovic called for a congressional investigation of Red State, saying that Ms. Van Laar’s reporting was “wildly irresponsible” and “probably should be illegal.” But if reporting facts about members of Congress becomes illegal, what would the First Amendment’s guarantee of a free press mean? And who was “wildly irresponsible” in this case, Katie Hill or the reporter who published these (not-yet-illegal) facts?

Perhaps most laughable in this saga was the accusation that it was wrong for Ms. Van Laar to act as a reporter because she is also a Republican. Red State, however, has never been secretive about its pro-GOP leanings, unlike CNN, which pretends to be engaged in neutral objective journalism while acting as a propaganda organ of the Democratic Party. And it’s not as if the indications of Ms. Hill’s personal problems would have been difficult for any diligent journalist to find.

That May 2018 HBO segment profiling her California campaign, for example, opened with a scene of the then-30-year-old candidate hugging and kissing her husband, Kenny Heslep. It featured interviews with Ms. Dejardins, the young campaign staffer who was at that time the trois in the Hill–Heslep ménage, and also with Kelly, who was the campaign’s finance director before moving to D.C. to join Ms. Hill’s congressional staff (and, allegedly, become her full-time lover). Are we to believe that none of the journalists who covered Ms. Hill’s campaign in 2018 suspected what her self-proclaimed “bisexuality” meant in practice?

God forbid, however, that any of the allegedly objective professionals in the political press corps should bother digging up any facts that might adversely impact the Democratic Party. Instead, they pliantly repeat whatever Democrats tell them, including Ms. Hill’s claim that she is the victim of an “abusive husband” (despite praising him as “the love of my life” in social media posts during her campaign). Democrats tell lies, the “fake news” media report these lies as if they were true, and everybody is supposed to pretend we don’t notice any discrepancies.

Goodbye, then, to Katie Hill, who leaves Washington the same way she came in — exit, lying.