So, John Edwards has thrown his hat into the presidential ring.

Unfortunately, he has a losing message.

His ultra-liberal approach will elicit only a small niche of support among the ultra-lefties in the Democratic Party.

Democrats know, or at least I think they know, that their success in the 2006 midterm election was largely a function of their best efforts to imitate Republicans. It was the conservative Blue Dog Democrats who were the tail successfully wagging the entire Democratic dog.

That said, if Mr. Edwards somehow manages to reverse this tide and win his party’s nomination, he would lead his party to a crushing defeat in 2008.

For starters, he wants to cut and run from Iraq. Such an ill-conceived policy would leave that budding nation in shambles with terrorists following us back to America. It would extinguish the candle of Iraq’s democracy experiment — an experiment that could still pay enormous dividends if America follows through with a bold, new troop-surge strategy and a refurbished plan of economic reconstruction. These are the actions that will stabilize Baghdad and Iraq’s democratically elected government, not cutting and running.

On the domestic side, Mr. Edwards fares just as badly. He’s recycling an old page from the liberal Democratic playbook, saying that he wants to make fighting poverty the great moral issue of our time. He says he’ll accomplish this by taxing the rich in order to help the poor. Oh, really?

Tax capital in order to create new jobs? Huh? Haven’t we learned that you can’t create new jobs for the poor or for anyone else without healthy businesses and plentiful new business creation? And that businesses require capital in order to expand? And haven’t we learned that punishing success through higher tax rates that make it pay less to work, save, and invest will only reduce investment, jobs, and prosperity?

Well, Mr. Edwards forgets that entrepreneurs, not government, create long-lasting jobs and growth. Rather than government spending, it is economic freedom, through a strong incentive structure inside a market economy, that opens the door to new opportunities so that the non-rich can get rich.

What’s more, Mr. Edwards has failed to consider that poverty has fallen steadily for decades.

Pro-growth, market-oriented policies launched by Ronald Reagan 25 years ago unleashed record wealth creation and economic growth that continues to this very day. In fact, charts accompanying a recent Wall Street Journal article on Mr. Edwards show that the lowest income 40% of households actually declined over the past 15 years. And economist Diana Furchtgott-Roth has shown that total compensation and consumer spending for all five income quintiles have steadily increased over the past three decades.

Furthermore, nationally syndicated columnist Alan Reynolds has shown that the percentage of households with income (adjusted for inflation) lower than $35,000 has actually fallen to 40.9% from 52.8% since 1967. Wait—it gets even better. Households with a real income higher than $50,000 rose to a remarkable 44.1% from 24.9%.

In other words, the middle class is shrinking because America’s families are getting wealthier. And the reason lower-class jobs are vanishing is not due to some Lou Dobbs, protectionist, conspiracy theory, but because our technologically driven, knowledge based, economic pie keeps expanding.

Mr. Edwards doesn’t understand that without incentives to reward successful investing, entrepreneurship, and risk-taking, everyone gets poorer — right on down the line. Additional investment taxing is precisely the wrong policy to improve wealth or poverty. Class warriors on the left are loath to admit it, but America’s poor are also a whole lot less poor when public assistance programs like Social Security, Medicaid, the Earned Income Tax Credit, and other social-benefit plans are included in the poverty data. But Mr. Edwards and others of his misguided ilk have a nostalgic yearning for the Great Society plans of the mid-1960’s. You’ll recall that these policies dramatically succeeded by raising poverty and reducing wealth. What a neat idea.

Mr. Edwards just launched his campaign in New Orleans with a plea to spend even more taxpayer dollars for that beleaguered city. Well, why not — we’ve already thrown $120 billion at it.

Instead of Mr. Edwards’ hackneyed, 1960’s Great Society, anti-poverty approach to New Orleans, America and New Orleans would have been much better off had we made the entire city a tax-free zone — with the tax burden limited only to what people spent or consumed, not what they invested or earned. This supply-side approach would have delivered swift currents of investment. It would have all but guaranteed a swift recovery.

But Mr. Edwards appears unable to grasp this. This class warrior fails to recognize that when you slam wealth, you raise poverty. Is that what we really want?

Mr. Kudlow is host of CNBC’s “Kudlow & Company.”