Robert Moses built as often with expressions and syllogism as with stone and steel. “The important thing is to get things done.” “If the end doesn’t justify the means, what does?” “Either you want it or you don’t want it, and either you want it now or you don’t get it at all.”

They peppered his conversations and correspondence and were bellowed at rooms full of subservient staff, intransigent politicians and hostile citizens. The most influential and enduring of his maxims is undoubtedly: “Once you sink that first stake, they’ll never make you pull it up.”

More than the thousands of miles of roads and bridges and tunnels, the grand parks and parkways, the exhibition centers and fairs, more than the innumerable demolished homes and displaced families, the congestion and pollution, the social unrest—more than anything that Moses built or destroyed, this idea, get the shovels in the ground and there will be no stopping us, shaped the country’s public works ethos.

While his projects were largely confined to New York, his ideas about how, and why, to build persisted across the country. Sure, there were the acolytes who parroted Moses’ ideas of urban renewal in cities across America, but they fell out of favor not long after their patron fell from power. His ideas, on how to build, and more importantly how to keep building, persisted for decades after Moses was deposed. For almost 30 years after he was laid to rest in 1981, Moses’ spirit lived on in infrastructure.

Sink those stakes, and the money will follow for more. It always does.

Then, almost over night, we gave up the ghost. It did not start with New Jersey Gov. Chris Christie and his decision to cancel the ARC Tunnel—recall the Congressional fight over much-maligned stimulus spending—but that was certainly the clarion call.

So what if the motivations were more political than practical? So what if Mr. Christie listened to the complaints of his wife about the 10 flights of stairs up from the new 34th Street station that she dreaded, rather than the counsel of transportation experts? Whatever the outcome of Mr. Christie’s decision to nix the tunnel—longer commutes, an abortive presidential run (twice!), more money for highways—the simple fact remains that he pulled up the stakes, and once he did, others began to follow suit.

During his election run in Wisconsin, Gov. Scott Walker launched NoTrain.com. An open letter, aimed at the president and his gubernatorial predecessor, declares, “I am drawing a line in the sand Mr. President: No matter how much money you and Governor Doyle try to spend before the end of the year, I will put a stop to this boondoggle the day I take office.” He returned the $800 million his state had been promised.

Florida Gov. Rick Scott went even further, turning down a $2 billion grant—almost as much as Mr. Christie gave up—that would have helped fund high-speed rail between Tampa and Orlando. This was the Obama administration’s signature stimulus project, bullet trains some day running from coast to coast, the kind our rivals in Europe and Asia are building with frustrating regularity, and here were some of the nation’s top political leaders turning their noses up at this free money.

What has gone missing is “the civic state,” as the great Moses biographer Robert Caro put it in an interview. “When you talk about building these things, it’s about improving the overall environment we live in,” Mr. Caro said. “It’s worth paying to do that.”

People have been declaring the death of Robert Moses while he was still alive and even while in power. However, America may be witnessing the true twilight of his influence, the final stake, this one through his heart. At a time when we need to be building, not only to repair our aging infrastructure, but to dig ourselves out of a recession, we are doing anything but.