If you don’t know Gary Johnson, you won’t learn much from the June 13 Republican debate.

CNN informed the Johnson campaign last week that the former New Mexico governor, who announced his presidential candidacy in April, would not be invited or allowed to participate.

It’s rare that I agree with a campaign press release. But Johnson’s campaign got it exactly right: his exclusion from the debate amounts to media (un)favoritism.

Admittedly, I’m more likely to be rankled by this than your average American: I’m a (tentative) supporter of Johnson. But in a field that is, by all accounts, wide open, snubbing a candidate does both the public discourse and the American polity a disservice.

Johnson’s early exclusion is a historical anomaly. Dark horses Mike Gravel and Alan Keyes were excluded from televised debates in the 2008 race — but only later in the campaign. Both Duncan Hunter and Tom Tancredo were polling at 1 percent in August 2007 — but still attended CNN’s Nov. 28 debate.

So why the difference? CNN’s exclusion of Johnson, I suspect, is based in “journalistic discretion.” The same kind of “discretion” that inflated Donald Trump’s sham candidacy: a flashy, celebrity-style approach to politics that ranks spectacle over substance.

Johnson, an unassuming man with a score of physical feats (and gubernatorial vetoes) under his belt, lacks the star power of Sarah Palin. He doesn’t have Mitt Romney’s gigawatt smile or polling numbers. He can’t measure up to the notoriety of unannounced presumed candidate Rick Santorum, who is about even with Johnson in the polls.

Simply put, if you prefer political theater to actual substance, he’s just not that interesting. And if the news media should know better, they haven’t in quite a while.

“The newspapers shout right along with their readers and seek to please when they ought simply to enlighten,” wrote French novelist Albert Camus, during his days as an editor and editorial writer of the underground newspaper Combat.

Analogous, perhaps, to the breathless, sensational coverage that accompanied Palin and Trump’s pizza meeting last week. Or the giddy reporters enthusing over Palin’s whirlwind bus tour (CNN political reporter Peter Hamby helpfully explained the necessity of taking Palin seriously.)

CNN’s snubbing of Johnson amounts to a disturbing new role for the network: that of political gatekeeper. When media networks focus exclusively on high-profile candidates, they reinforce the presence of those candidates in the mind of the American public. It would be difficult to argue that Johnson should be given equal coverage to the front-runners, but inclusion in debates — a medium for his message — should be taken for granted.

“The argument for the defense is well known,” wrote Camus.“ ‘We give the public what it wants.’ But this isn’t what the public wants. It’s what the public has been taught to want, which isn’t the same thing.”

Camus could be speaking of today’s major news outlets. If members of the media establish politics as a competitive spectacle, an all-star sport, the spectators will demand celebrity athletes. But democracy is not a spectator sport, and it only functions when citizens are informed of all perspectives.

Including the perspectives of dark horse, long-shot candidates such as Johnson.