The New Deal is 75 years young this month.

A host of commentators have invoked the current mortgage credit crisis as justification for a sweeping intrusion of the government into the economy, not just into the credit markets. American Prospect editor Harold Myerson says, "Bring on the new New Deal."

For all this talk of newness, you might be surprised at how old the idea is. Liberals were calling for a "new New Deal" when the first New Deal was barely out of diapers. That's one reason FDR launched a "second New Deal" from 1935-1937. In 1944, he attempted to jump-start a third New Deal with his "second Bill of Rights."

Let's set aside Harry Truman's "Fair Deal," JFK's "New Frontier," LBJ's "Great Society" and Bill Clinton's "New Covenant." I'm sure Jimmy Carter had something like this, too; I just try to avoid paying any attention to the man.

Even the New Deal wasn't as new as many claimed (as I argue in my book, "Liberal Fascism"). FDR himself sold the New Deal as a continuation of the war socialism of the Wilson administration, in which FDR had served. For example, the Tennessee Valley Authority, the signature public-works project of the New Deal, had its roots in a World War I power project. (As FDR explained when he formally asked Congress to create the thing, "This power development of war days leads logically to national planning.")

Since George W. Bush was elected, liberals have been calling for new New Deals more frequently than my daughter asks "are we there yet?" whenever we're in the car. After 9/11, Sen. Charles Schumer argued that the terrorist attack proved the need for a new New Deal, and that "the president can either lead the charge or be run over by it." After Hurricane Katrina, left-wing journalist William Greider spoke for many when he said that the natural disaster required a "new New Deal." Last January, Chicago Mayor Richard Daley said the looming recession was all the excuse government needed. The head of the Democratic Congressional Campaign Committee, Rahm Emmanuel, wrote last January that we need "a New Deal for the New Economy" that provides everything from universal health care to sweeping job training, in response to globalization.

Now it's the financial crisis that requires a you-know-what.

It's like liberals are playing a game of "Jeopardy" where the response to every question is, "What is a new New Deal?"

Still, it's worth noting for the record that the New Deal didn't really do what most of these people think it did. It didn't, for example, end the Great Depression. It prolonged it - by years. It didn't really crack down on big business - it gave big business unprecedented power to regulate itself, to the detriment of small businessmen.

But when you point out these facts, the usual response is, "So what?"

Well, if you're going to proclaim that what we need is a new New Deal when you're conceding that the New Deal didn't work, you've got a problem on your hands.

But the problems go deeper than that. Some say what they love about the New Deal was its "bold, persistent experimentation," in FDR's famous words.

"We need our leaders to recapture the urgency of the New Deal era, an enthusiasm for experimentation that attempts to address Americans' core challenges and not just win elections," writes Andrea Batista Schlesinger in the April 7 issue of The Nation.

Others, like Emanuel, suggest that "planning" was the essence of the New Deal. But planning and experimentation are, in fact, opposites. You don't "experiment" when performing an appendectomy or when building a house; you follow a plan.

More important, these New Deal nostalgists don't like experiments in the first place. It's all one-way, about finding new ways to expand government, not new ways to solve problems. Experiments like school vouchers or social security privatization: These are completely taboo to the same people clamoring for a new New Deal.

Others will tell you that what was great about the New Deal was its spirit of "hope" and "unity" - two words we hear a lot these days. But hope for what? Unity about what?

The answer is obvious. The hope for power that comes with unity. "Experimentation" is really just a dishonest word for allowing the would-be Brain Trusters to do whatever they want. And if it fails, well, that's no reason to take away their licenses, because they warned us they were "experimenting."