He can do this because members of the Trump administration feel confident that the alternative-reality media will provide air cover, even if they are caught fabricating facts or twisting words (like claiming that the “ban” on Muslim immigrants wasn’t really a “ban”). Indeed, they believe they have shifted the paradigm of media coverage, replacing the traditional media with their own.

In a stunning demonstration of the power and resiliency of our new post-factual political culture, Mr. Trump and his allies in the right media have already turned the term “fake news” against its critics, essentially draining it of any meaning. During the campaign, actual “fake news” — deliberate hoaxes — polluted political discourse and clogged social media timelines.

Some outlets opened the door, by helping spread conspiracy theories and indulging the paranoia of the fever swamps. For years, the widely read Drudge Report has linked to the bizarre conspiracy theorist Alex Jones, who believes that both the attacks of Sept. 11 and the Sandy Hook shootings were government-inspired “false flag” operations.

For conservatives, this should have made it clear that something was badly amiss in their media ecosystem. But now any news deemed to be biased, annoying or negative can be labeled “fake news.” Erroneous reports that the bust of the Rev. Dr. Martin Luther King Jr. had been removed from the Oval Office or misleading reports that sanctions against Russia had been lifted will be seized on by Mr. Trump’s White House to reinforce his indictment.

Even as he continues to attack the “dishonest media,” Mr. Trump and his allies are empowering this alt-reality media, providing White House access to Breitbart and other post-factual outlets that are already morphing into fierce defenders of the administration.

The relationship appears to be symbiotic, as Mr. Trump often seems to pick up on talking points from Fox News and has tweeted out links from websites notorious for their casual relationship to the truth, including sites like Gateway Pundit, a hoax-peddling site that announced, shortly after the inauguration, that it would have a White House correspondent.