What a train wreck.

Last week, the rollout of the Green New Deal brought sustained attention to the idea of high-speed rail in the United States for the first time since the early years of the Obama administration. Various Democratic presidential contenders endorsed, albeit in the vaguest possible terms, the idea of getting more people to more places via faster and more dependable train service. The office of Rep. Alexandria Ocasio-Cortez went one further, suggesting—by mistake, apparently—that a souped-up rail system could replace domestic air travel.

D’oh. A GOP meme was born. “The authors of the Green New Deal assume that technocratic planners can master the movements of 328 million Americans and design a transportation system so that ‘air travel stops becoming necessary,’ ” David Brooks jabbed in the New York Times. “This is from people who couldn’t even organize the successful release of their own background document.” By the time Rep. Liz Cheney discussed the plan on the House floor, Democrats were planning to “outlaw air travel” within the decade.

That was fancy. But reality wasn’t on the Democrats’ side either. On Tuesday, California Gov. Gavin Newsom announced he would be truncating the nation’s flagship public high-speed rail project, the train from Los Angeles to San Francisco, to run between … Bakersfield and Merced. Driving that great strawberry patch takes just 2½ hours.

It’s a staggering step back from the plan as it was envisioned more than a decade ago, and it feels like a blow to the idea that high-speed rail can meaningfully compete with air travel beyond the Northeast Corridor. It shouldn’t: High-speed rail is in fact eating into domestic airline industries from Italy to China, making travel easier, cheaper, faster, and cleaner. Modern, purpose-built high-speed rail has captured 90 percent of the market between Paris and Lyon (267 miles) and 85 percent of the market between Tokyo and Osaka (320 miles). Insert your favorite short-distance U.S. airline route here.

But first you have to lay the tracks.

In 2008, California voters approved a $10 billion bond for a new train route between the Southland and the Bay. At the time, the project was supposed to cost $32 billion and finish in 2029. Last year, a revised business plan had it at $77 billion, finishing in 2033. The state broke ground on the 119-mile Central Valley segment in 2015, but still hadn’t acquired all the land in the corridor as of last year. The entire route is 520 miles.

To Californians who have followed the project, Tuesday’s announcement comes as no surprise. In December, Newsom professed his support for the so-called “Valley-to-Valley” section of the California project, the first to break ground, but otherwise thought it was “time for a fresh start.”

“What Newsom said today wasn’t news. It was news that he said it out loud,” said Nadia Naik of the grassroots group Californians Advocating Responsible Rail Design, which supports the high-speed rail plan but has argued for greater transparency and accountability. “For Californians, it’s really sad. We knew California could be a model and that if we screwed this up, people would point and say we shouldn’t do that. All the fears have come to pass.”

What makes this failure so biting for environmentalists and rail advocates is precisely the fact that high-speed rail projects around the world have proven to be exactly what Ocasio-Cortez’s office suggested: major threats to domestic airline routes. A broader lesson is that the greatest threat to a progressive national agenda lies with its own incompetent administrators.

Opponents of high-speed rail often invoke some kind of American exceptionalism, arguing that America is too big, too dispersed, and too car-dependent to have a market for intercity train travel. In reality, the only American exceptionalism is our debilitating lack of expertise. “I’ve always quoted Churchill when it comes to high-speed rail,” says Anthony Perl, a professor at Simon Fraser University in Vancouver, British Columbia. “The Americans can always be counted on to do the right thing after they’ve exhausted all the alternatives.”

A recent overview of research suggests that planes and high-speed trains are competitive on routes under 600 miles. Internationally, that includes routes like Rome–Milan, Tokyo–Osaka, and Paris–London. Domestically, it might include Atlanta–Charlotte, Los Angeles–Las Vegas, and, yes, Los Angeles–San Francisco. Under 300 miles, rail becomes dominant. “Several regions in the United States have comparable density that might support the success of high-speed rail,” says Yu Zhang, one of the report’s authors. Park-and-ride, Uber and Lyft, transcontinental flights, and short-haul, low-ridership airplane shuttles should all be viewed as complements to new high-speed rail, which is often linked to airports as well as city centers.

Even long routes can succeed if passengers are willing to sacrifice a couple of hours for the comfort of the train. Beijing–Shanghai is only a bit shorter than New York–Chicago (though with more forgiving terrain—a U.S. version would have to trace the old Erie Canal). At 4½ hours, it’s one of China’s most popular and profitable routes.

California’s project had little in common with its peers in France or China. “You hear a lot about best practices,” says Jeff Davis at the Eno Center for Transportation, a think tank in Washington. “This particular California project has a series of worst practices.” Those include:

• A meandering route through the Central Valley devised to win support at the ballot box, locking planners into a scheme that took the route away from its goal of connecting the state’s biggest cities.

• A mad rush to begin construction without knowing the route, acquiring the right of way, studying the geology, or securing the funding.

• An irresponsible partner in the federal government that rushed California to get going and encouraged the state to proceed with half-baked plans.

• A balkanized planning process teeming with eager private-sector beavers who were afraid to report how flawed the enterprise was, a system that Naik called “no consultant left behind.”

• The determination not to engage French and Chinese engineers who offered to just build the damn thing for us. “The equivalent of Bangladesh saying they’d go to the moon with indigenous technology” is how Perl describes the general attitude. “We excluded all the learning and tech that happened elsewhere.”

Is there reason to be optimistic? Perhaps: Newsom’s promise to bring transparency to the high-speed rail project can serve as a teachable moment for the state and others that want to follow in its footsteps. “It’s a very expensive misstep,” says Naik. “But if Gavin Newsom is able to make a real change, and get more accountability, it’s probably worth more to California than any amount of rail.” Once a useless Central Valley spur is in place, there might be appetite to try again. (We could ask the Japanese to clean up our mess.)

Critics will whine, as they always do, that high-speed rail can’t pay for itself. The evidence suggests it hasn’t and won’t. (Though a private company is trying in Texas.) But neither do highways or airports, especially when you account for their enormous externalities. Democrats are right to want to subsidize the development of a transportation mode that brings us less close to a global meltdown than the other subsidized transportation mode. Once operating, many high-speed rail routes are self-sufficient, with ticket sales covering operations and maintenance. What makes the failure in California so frustrating is not that it was crazy to suggest the train could sharply curtail California’s intercity air travel—but that it might have, if we’d done it right.