Don't look now, but someone accidentally let a genuine policy disagreement erupt between the Democratic candidates.

And it's telling that the dispute exposes a fact neither candidate will admit: namely, that Americans are overtaxed.

The quarrel is about a proposed gas tax holiday, a short-term fix supported by Hillary Clinton (and, in another form, by Republican John McCain.) It is estimated the tax holiday would cost the federal Highway Trust Fund around $9 billion used to maintain roads and bridges.

Many economists consider it a terrible idea. The savings for consumers would be minimal — and even if it worked, the demand for gas would rise at the most inopportune time.

The gas tax, moreover, is one of the few levies that functions as a toll rather than flowing into some leaky pot never to be heard from again.

Barack Obama sprang to action, calling the gas tax holiday a political "scheme" — though he supported a similar "mistake" in Illinois — and the sort of unsightly pandering that "passes for leadership in Washington, phony ideas, calculated to win elections instead of actually solving problems."

Obama is correct. And he demonstrated precisely how phony calculated ideas work by offering his very own — a bigger and better rebate plan than one signed by President Bush. In this scheme, politicians pretend they're doing you an enormous favor by handing back too little of your own money.

But what this conversation does reveal, whether the candidates like it or not, is that citizens are unreasonably burdened by taxes and that tax relief is often the way to stimulate economic growth.

As the Washington, D.C.-based Tax Foundation notes, Americans work nearly four months of the year, from Jan. 1 to April 23, just to pay off their taxes. On average, an American will pay more in taxes than they do housing, transportation, health care — or gratuitous expenses like entertainment and children.

Meanwhile, the federal budget grows. Washington runs on a deficit. Voters demand more. And candidates offer quixotic plans to "solve problems" for untold billions.

For Democrats, "progress" often means expanding or inventing entitlement programs. For Republicans, tax cuts are nearly sacrosanct. The problem, of course, is that spending is wholly sacrosanct. Yet someone somewhere has to pay for the War on Nouns.

But who? The solutions we often hear are based on two canards.

First: "Let's tax those rich people. They don't pay their fair share."

It bears repeating that the top 1 percent of wealthiest American earners earn 19 percent of the income but pay 37 percent of the income taxes. The top 10 percent of earners pay nearly 70 percent of all income taxes. Meanwhile, the bottom 50 percent of earners pay 3 percent. That seems more than "fair."

The second canard: "Let's tax scummy corporations; they never pay their fair share." Both Democratic candidates talk about potential windfall taxes, and all three candidates have resorted to demagoguery about excessive profits.

Another Tax Foundation study shows that, counting the federal rate alone, the U.S. already has the world's highest corporate tax rate. Most nations have learned that high corporate taxes discourage business, encourage outsourcing and are, inevitably, passed on to consumers.

All candidates claim a special ability to "solve our problems." Most of their proposed fixes carry exorbitant price tags. Presidential hopefuls rarely, if ever, explain how we are going to fund these future nirvanas.

But despite all their flaws, it is heartening that both Obama and Clinton's plan for economic assistance was based, however tepidly, on the premise that tax relief can help stimulate the economy.

That fact, surely, says more about the economy than either candidate ever intended.

Reach columnist David Harsanyi at 303-954-1255 or dharsanyi@ denverpost.com.