Saturday’s Spirit Airlines shutdown is entirely on the Biden administration — and more specifically, on the faux-populism of its Federal Trade Commission chief, Lina Khan.

On top of all the travelers left scrambling, 17,000 Americans just lost their jobs, while future travelers will have one less choice and the rest of the industry faces reduced competition.

No, Spirit’s bare-bones approach wasn’t for everybody (paying for every checked bag rubs many the wrong way), and perhaps the business was always doomed — but there was no need for its end to be this cruel.

Khan and then-Transportation Secretary Pete Buttigieg cheered as the Biden Justice Department blocked JetBlue’s bid to buy Spirit in 2024, arguing that the “industry consolidation” would be bad for consumers.

Democrats eager to shift the blame point to how the Iran war sent fuel prices surging, but that at most explains the timing of Spirit’s death: It had been struggling for years, including two bankruptcies.

The sale of Spirit would’ve at a minimum been smoother for consumers and employees, and likely left JetBlue better able to challenge the major carriers (American, Delta, Southwest and United) that control most of the US market.

Instead, the Big Four are now a bit more powerful.

The Khan crew didn’t see that, because they rely on simplistic theories at odds with how the world really works — is it any wonder that Lina has a huge fan in Mayor Zohran Mamdani?

Claiming to stand up for the little guy is very different from delivering for him — indeed, abstract theorists have a habit of crushing the very folks they claim to protect.

Beware: Khan has a few fans on the right, as well — folks with reasonable worries about overly dominant corporations who sympathize with her professed motives.

Let the death of Spirit be a warning to all: Good intentions paired with arrogant moralizing are a recipe for disaster.