(FORTUNE Magazine) – America's rich have been taking a pounding lately, and it's time someone spoke up for them.

That sounds like a joke setup, but actually I mean it. The election-year nonsense has begun, and you'll be hearing plenty of misinformation from both parties about wealth, taxes, and burden bearing. Those vital topics include several important and surprising facts that it's in no candidate's interest to tell you but that it's definitely in your interest to know. So let's get to them.

Are the rich getting away with economic murder? John Kerry, accepting the Democratic nomination, made several ambitious promises: halving the budget deficit while cutting taxes on the middle class and small business and increasing spending on job creation, health care, and education. To pay for it all, he proposed only one tax increase: "I will roll back the tax cuts for the wealthiest individuals who make over $200,000 a year."

The idea that the rich get richer through good times and bad while conniving to pay ever lower taxes is a common one. A recent New Yorker cartoon shows a group of the Founding Fathers apparently drafting the Constitution; one of them, looking a bit like Benjamin Franklin, says, "Can't we put in something about rich white guys don't have to pay taxes?"

But the caricature of tax-free plutocrats isn't accurate. Just-released IRS data show that during the bad economic years of 2001 and 2002, the Americans who got whacked hardest were precisely the $200,000-plus earners Kerry is targeting. The incomes of the broad middle class, those earning $25,000 to $200,000, actually increased slightly during that period, in the aggregate and per taxpayer, on average. But those making $200,000 and up suffered significant drops in income--and the higher the income level, the steeper the plunge.

That reversal of fortune did them no good income tax--wise. You might think that under a progressive income tax structure like ours, when your income declines, you pay a smaller percentage of it in income tax. That's the theory. But what happened was exactly the opposite. The $200,000-plus group, as their incomes got clobbered in 2001 and 2002, actually paid a higher percentage in income tax. They got clobbered twice.

Which brings us to the topic that candidates really don't want to talk about: the share of the tax burden borne by the rich. Winning an election is all about courting the middle class, which is where the votes are. So each party's campaign managers will instruct their ticket of multimillionaires to don workshirts and tell middle-class voters how they're the bedrock that supports this country. And in many respects they are--but not when it comes to income taxes.

The simple reality, which you're unlikely to hear from any candidate, is that much of America pays no income tax at all. A fact many people find astonishing is that the 40% of Americans with the lowest incomes actually have a negative income tax rate--in the aggregate they pay nothing and instead get money back through the Earned Income Credit.

Consider this perspective: If you lined up Americans from lowest income to highest, and then, starting at the bottom, worked your way up, calculating the net position of the U.S. Treasury as you went, you would work your way through more than 50% of the U.S. population before the Treasury, on net, took in a dime of income tax.

So where does the federal government get its money? You guessed it: The 20% of Americans with the highest incomes took in 52% of total income but paid 83% of America's income taxes in 2001. The top 10% paid 70% of total income taxes. The beleaguered $200,000-plus group were just 2% of tax filers and made 23% of total income, but they paid 41% of total income taxes.

Certainly the picture of taxes in America is more complex than this. Do some of the rich avoid paying their fair share by torturing the tax code? Absolutely. Do the poor get hammered by regressive levies like Social Security and excise taxes? They sure do. Those problems are worth debating and fixing.

But as the election campaign progresses, try hard to keep the big picture in mind. It's important. But because it isn't a vote getter, hardly anyone wants to tell you about it.

GEOFFREY COLVIN, senior editor at large of FORTUNE, can be reached at gcolvin@fortunemail.com. Watch him on Wall $treet Week With FORTUNE, Friday evenings on PBS.