UNTIL last year’s vote, Mr. Domenici was an opponent of new fuel-efficiency standards, a stance he now regards as a mistake. “We were like everybody else,” he says. “We should have been more active on CAFE sooner.”

With Detroit again seeing profits collapse as sales of big cars plunge, Mr. Domenici says he is worried about the survival of the domestic automakers.

“They talked a good research game,” he says. “But let’s face it, little was being done. They are suffering the consequences and could go broke just like the airlines.”

What Congress didn’t or couldn’t do, the free market is now doing in the form of higher gas prices: forcing Americans into more fuel-efficient cars. Ms. Cischke of Ford says that in the last two months, “We have seen more of a shift in the market than in 20 years of CAFE. People are buying what they need.”

Unfortunately, the shift is happening too fast for a company of Ford’s size. That is among the reasons Wall Street expects Ford to lose more than $2 billion this year.

Congress, meanwhile, in its bid to explain the run-up in fuel prices, is examining the role of speculation and the increased flow of investor money into commodities. Most energy economists emphasize the fundamental issue of supply and demand, rather than market manipulation, but financial factors like the weak dollar are also exacerbating the situation. Stephen P. A. Brown, director of energy economics and microeconomic policy analysis at the Federal Reserve Bank of Dallas, estimates that a little more than 20 percent of the price of oil today can be attributed to the dollar’s fall against the euro and other currencies.

Another financial factor behind the price rise that hasn’t been talked about much on Capitol Hill or elsewhere is reduced hedging by oil companies on futures markets, says Larry Goldstein, a longtime energy analyst. In the past, crude producers would offer buyers a portion of their energy output in future years in order to protect themselves if prices pulled back. But energy companies got burned as prices kept rising during the last two years and have since cut back on selling untapped production  forcing prices for energy futures even higher.