The small cartoon on the Tax Policy Center’s website shows a man’s head with a gaping hole through it and the words "Stupid Tax Trick." The words refer to the proposal by Sen. John McCain to suspend the 18.4 cents per gallon federal excise tax on gasoline between Memorial Day and Labor Day.

The presumptive Republican presidential nominee’s suggestion was quickly picked up by Sen. Hillary Rodham Clinton, campaigning for the Democratic nomination. The idea, however, died a quick death in the Senate at the hands of a Democratic caucus drafting a bill aimed at giving relief from soaring gas prices. To many economists and others, the short tax holiday didn’t make much sense.

"It’s a terrible idea," says economist Eric Toter, coauthor of the article that accompanied the cartoon and was headlined, "What Were They Thinking???"

Undoubtedly, they were thinking politics. A new survey by the Kaiser Family Foundation found that paying for gasoline easily tops the list of economic woes seen by American families. Some 44 percent of those surveyed saw their gas bills as a "serious problem."

"It’s out of the political pandering playbook," says Robert Bixby, executive director of the Concord Coalition, a nonpartisan organization pushing for elimination of the federal budget deficit.

Here’s why critics say the gasoline-tax holiday plan is a bad idea:

• It wouldn’t save the average consumer much money. If a driver uses 10 gallons a week, he or she would save about $26 during the three months – enough to buy seven or eight milkshakes. A driver with a long commute to work would, potentially, save more. So would the truck drivers who were circling the Capitol in a horn-blaring caravan a couple of weeks ago. (The tax on diesel is 24.4 cents per gallon.)

The problem, says Toter, is that the cheaper fuel would encourage Americans to drive more – say an extra trip to the beach. The end result – after increased summer demand stretches American refining capacity to the limit – would be even higher prices.

It wouldn’t "do anything" for the consumer, Toter concludes. It would just boost the already record profits of refiners and oil companies.

An econometic analysis by Jeff Perloff, an economist at the University of California, Berkeley, is not so harsh. Drivers might save 9 to 12 cents a gallon despite the rising demand, he reckons.

• The gas-tax break would do nothing about United States dependence on imported oil, or, for that matter, on a limited supply of domestic oil. Contrariwise, it would add to consumption and to global-warming emissions.

"We are the laughing stock of Europe because we keep [gasoline] taxes so cheap," notes Matthew Simmons, chairman of a Houston-based investment bank for the energy industry, Simmons & Co. International.

The state gasoline tax, which in Arizona is 18 cents per gallon, added to the federal tax totals 36.4 cents per gallon, which is less than the national average of 47 cents per gallon but way low by European standards. In Germany, for example, gas is taxed at about $2 per gallon.

Only last January, a bipartisan commission appointed by Congress recommended a 40-cent boost over five years in the federal gas tax with revenues used to improve the nation’s transportation system.

• The tax break would add to the federal deficit. Gas-tax revenues normally go to the Highway Trust Fund, which is used to maintain and improve the highway and public transit systems. One proposal in Congress would have substituted Treasury revenues for the lost Highway Trust Fund money.

• The change would be an administrative nightmare for the nation’s retail sellers of gasoline.

"It would be a logistical challenge," says Jeff Lenard, spokesman for the convenience stores that sell 80 percent of the nation’s gasoline supply.

For now, Washington is looking for other ways to hold down gasoline prices. Last week, Congress voted to stop filling the Strategic Petroleum Reserve. At present it contains 701 million barrels, enough with private oil company reserves to substitute for imported oil for 118 days. It was being filled at a rate of 70,000 barrels daily, not a hefty amount compared with imports of 10.1 million barrels a day.

"We are addicted to petroleum, a source of energy which is gradually going to disappear," warns Michael Klare, who teaches international affairs at Hampshire College in Amherst, Mass. He says the United States must really work on "alternative" energy sources.

That’s not a short-term solution.

Contact David R. Francis at francisd@csps.com. His nationally syndicated commentary on finance and government issues appears the third week of each month.