Charlie Gibson, finest debate moderator of this election

We thought the debate was one of the best yet, precisely because it probed the evasive rhetoric we've heard from both Democratic candidates throughout the campaign. Nowhere was this more apparent than during the exchanges between Mr. Gibson and Mr. Obama over taxes.

Time and again, the rookie Senator has said he would not raise taxes on middle-class earners, whom he describes as people with annual income lower than between $200,000 and $250,000. On Wednesday night, he repeated the vow. "I not only have pledged not to raise their taxes," said the Senator, "I've been the first candidate in this race to specifically say I would cut their taxes."

But Mr. Obama has also said he's open to raising – indeed, nearly doubling to 28% – the current top capital gains tax rate of 15%, which would in fact be a tax hike on some 100 million Americans who own stock, including millions of people who fit Mr. Obama's definition of middle class.

Mr. Gibson dared to point out this inconsistency, which regularly goes unmentioned in Mr. Obama's fawning press coverage. But Mr. Gibson also probed a little deeper, asking the candidate why he wants to increase the capital gains tax when history shows that a higher rate brings in less revenue.

"Bill Clinton in 1997 signed legislation that dropped the capital gains tax to 20%," said Mr. Gibson. "And George Bush has taken it down to 15%. And in each instance, when the rate dropped, revenues from the tax increased. The government took in more money. And in the 1980s, when the tax was increased to 28%, the revenues went down. So why raise it at all, especially given the fact that 100 million people in this country own stock and would be affected?"

Mr. Obama answered by citing rich hedge fund managers. Raising the capital gains tax is necessary, he said, "to make sure . . . that our tax system is fair and that we are able to finance health care for Americans who currently don't have it and that we're able to invest in our infrastructure and invest in our schools. And you can't do that for free."

But Mr. Gibson had noted that higher rates yield less revenue. So the news anchor tried again: "But history shows that when you drop the capital gains tax, the revenues go up?" Mr. Obama responded that this "might happen or it might not. It depends on what's happening on Wall Street and how business is going." And then he went on a riff about John McCain and the housing market.

As the nearby chart shows, when the tax rate has risen over the past half century, capital gains realizations have fallen and along with them tax revenue. The most recent such episode was in the early 1990s, when Mr. Obama was old enough to be paying attention. That's one reason Jack Kennedy proposed cutting the capital gains rate. And it's one reason Bill Clinton went along with a rate cut to 20% from 28% in 1997.

Either the young Illinois Senator is ignorant of this revenue data, or he doesn't really care because he's a true income redistributionist who prefers high tax rates as a matter of ideological dogma regardless of the revenue consequences. Neither one is a recommendation for President.

Senator Obama was very impressive in 2004 when running for the Senate, and still impressive when he was listening to his best adviser. Now he's listening to his base, which will secure him votes, but at the price of a beneficial policy for all Americans.

One of the most important things for individuals and families is job creation. Either Obama is going to destroy jobs as president, or else he is a combination of disingenuous and way over his head.