ANALYSIS/OPINION:

Socialist revolutionaries are usually in a hurry. They ram through radical political, economic and social change, lest progressivism’s march slows or halts completely.

At the same time, history has taught them that when moving against societies with durable and cherished traditions of liberty and free-market economics, they must first acclimate those publics to statist ideas before they can actualize them as policy. The revolutionaries’ desire for speed exists in constant tension with the need for gradual conditioning of the masses.

This is precisely the blueprint for today’s American socialists, who move with both a predictable urgency and calculated methodology as they try to steer the nation away from limited government, capitalism and individual liberty and toward centralized control, command economics and collectivism.

It was former President Barack Obama — not Sen. Bernie Sanders — who turned the Democratic Party into a vehicle for neo-socialism and made unadulterated leftists like Rep. Alexandria Ocasio-Cortez, New York Democrat, possible. Given his unique persona, Mr. Obama was able to cleverly disguise socialism as a hip, virtuous-sounding pragmatism, based on themes of equality and social justice.

He then used his considerable rhetorical gifts to sell longstanding progressive ambitions, from massive government spending and higher taxes to suffocating regulation, socialized medicine and government-subsidized unproven green energy projects.

None of these policies delivered on their false promises, but that was beside the point. The point was to get the American public habituated to the idea of mammoth redistributist policies.

The left relentlessly labors to move the Overton window so that what was once considered unthinkable becomes idealized and preferred, as do those who promote it. They intentionally tout the extreme in order to elicit thundering condemnation so they can then look “reasonable” by “settling” for some part of their original proposal. That, in turn, establishes a precedent for pushing forward until they achieve what was previously considered the extreme.

So it is with the left’s “Green New Deal.” Proposed as a socialist revolution by way of an energy revolution by Miss Ocasio-Cortez and Sen. Ed Markey, its defining elements include eliminating all fossil fuels, replacing or retrofitting every building in America, “get[ting] rid of farting cows and airplanes,” “replacing every combustible-engine vehicle” and providing “economic security” to people “unwilling to work.”

The plan was immediately mocked as preposterous and declared “dead on arrival.” But its achievability is not its point. It’s not about an energy reformation. It’s about government power and control, which is why, despite minuscule public support, many prominent Democrats, including most of the Democratic 2020 hopefuls, have openly embraced it.

We’ve seen this movie before, in which the far-left proposes something ludicrously fanciful, knowing it won’t be embraced immediately. The goal is to inject it into the public bloodstream so that when they push it again, it’s no longer novel or controversial. That makes it more likely to be adopted, even if done piecemeal.

This was their approach with Obamacare. Their ideal vision has always been single-payer, in which the government runs every aspect of health care. In 2003, Illinois state senator Barack Obama laid out the strategy: “I happen to be a proponent of a single-payer universal health care program. But as all of you know, we may not get there immediately. Because first we have to take back the White House, we have to take back the Senate, and we have to take back the House.”

Once they captured all three, the left moved quickly to achieve the politically practicable while simultaneously accustoming the public to the pie-in-the-sky single payer idea.

Many of them admitted as much. After Obamacare’s 2010 passage, Sen. Tom Harkin referred to it as a “starter home.” Speaker Nancy Pelosi teased, “Once we kick through this door, there’ll be more legislation to follow.” Mr. Obama himself advised patience: “We’ve gotta start somewhere.”

They were right: Obamacare’s tentacles began to wrap around the economy, making it ever-more difficult to disassemble and accelerating widespread acquiescence of government control of health care. They knew that once that happened, acceptance of single payer wasn’t far behind.

And they were right again: most prominent Democrats now openly embrace single payer, rebranded as “Medicare for all.” And polling shows support for it climbing, as they intended.

This is exactly the pattern the left is following with the Green New Deal. It’s easy to laugh at something so patently absurd when it first debuts. But the left is playing the long game. It’s setting the groundwork for securing the much bigger power play down the road. As former Massachusetts Rep. Barney Frank admitted, “There’s an argument that you don’t destabilize a society by doing too much change at once.”

In America, the left knows it can’t just spring socialism on the land. They must accustom people to their most grandiose projects while maneuvering the politics and grinding away at public opposition.

Miss Ocasio-Cortez and her comrades expect us to ridicule then ignore her silly Green New Deal while they work tirelessly to make it a reality. So unless we’re willing to cede our most fundamental freedoms — which often manifest in things like cars, air travel, hamburgers and private health insurance — we must get as serious about their hostile takeover as they are.

• Monica Crowley is a columnist for The Washington Times.