Though Democrats put their more moderate face forward – keeping 110-proof liberals like Teddy Kennedy, Al Sharpton and Howard Dean out of primetime – they appear to have gained little or nothing from their Boston convention.

Newsweek gives Kerry-Edwards a four-point bounce out of Boston, to a 49-42 lead over Bush-Cheney. But the more venerable Gallup Poll says Kerry went into the convention ahead 47-46 and emerged trailing Bush 50-46, a loss of five points, unprecedented in modern convention history.

Why? Among the reasons in this writer’s judgment is that, while Kerry delivered the speech of his life at Boston, the man is simply not credible. When the basic math is done, the gap between his promises and what he can plausibly deliver is so transparently huge he ought to be hauled before the Federal Trade Commission for consumer fraud.

Consider. Last week, we learned the projected deficit for the year ending Sept. 30 will be $440 billion. Washington is taking in tax revenue roughly equal to 16 percent of GDP, but spending 20 percent of GDP.

Kerry promises to cut this deficit in half. Thus he must either raise $220 billion a year in new taxes or cut spending $220 billion, or some combination of both. But look at the spending binge Kerry-Edwards proposed in their addresses to the Boston convention. Here are Kerry’s promises.

  • “We will add 40,000 active duty troops … double our Special Forces and … provide our troops with the newest weapons …”

  • “I will cut middle-class taxes.”

  • “I will reduce the tax burden on small business.”

  • I will grant “a tax credit to families for each and every year of college.”

  • I will make health care a “right for all Americans” – i.e., guarantee health care to 45 million Americans now uninsured.

  • “Our health care plan will save families $1,000 a year in premiums.”

  • “Our energy plan will … invest in new technologies and alternative fuels … so that no young American in uniform will ever be held hostage to our dependency on oil from the Middle East.”

Kerry also promised fresh money for Head Start, Early Start and Smart Start, tax rewards for companies that keep jobs in the United States, tax incentives to revitalize manufacturing and new investments in technology to create the jobs of the future.

To these goodies John Edwards added, “We are going to help cover the rising costs of child care with a tax credit of up to $1,000 … [and if] your child wants to go to college, we’re going to give you a tax break of up to $4,000 in tuition.”

Consider what Kerry and Edwards are promising us. They are going to take today’s $440 billion deficit, add hundreds of billions of dollars in new spending each year, gut the U.S. tax base by scores of billions with tax cuts and credits for the middle class and small business – and end up with a deficit cut in half.

Where are they going to get the trillions of dollars in new tax revenue, over four years, they will need to do all this?

Said Edwards: “We are going to keep and protect the tax cuts for 98 percent of Americans. We going to roll back the tax cuts for the wealthiest Americans. We’re going to close corporate loopholes. We’re going to cut government contractors and wasteful spending.”

Fine. But what “loopholes” is he talking about? Which contractors are they going to fire? Besides Halliburton. And what “wasteful spending”?

The only solid source of new revenue Kerry-Edwards propose is to cancel the Bush tax cut for the top 2 percent of earners, those who make more than $200,000 a year. But as the Bush tax cut slashed that top rate only from 39.6 percent to 35 percent, we are not talking vast sums here.

Moreover, the marginal income of America’s most successful is a primary source of savings and investment. Who would you prefer to have planting the seed corn of the U.S. economy? John Kerry, Charlie Rangel and Teddy Kennedy – or Bill Gates?

With the first of 77 million baby boomers reaching 62 and early retirement in the next presidential term, Social Security and Medicare spending is about to explode. Kerry promises no cuts in either program, but big increases in spending for health, education, energy and an enlarged military, plus tax credits for a huge middle class that will swallow up any tax revenue from that 2 percent.

Oh, yes, and he is going to cut the $440 billion deficit in half.

“No one ever went broke underestimating the intelligence of the American public,” said H.L. Mencken. Apparently, Kerry and Edwards figure they can win the big enchilada that way. They may be right. We’re gonna find out.

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