Exxon Mobil (XOM) shares were down Tuesday because the oil giant posted worse-than-expected quarterly results. For investors, though, this is not necessarily bad news, as it may quell calls to make the oil industry pay higher taxes.

President Barack Obama and other Democrats argue that the government should strip away decades-old subsidies for the oil industry in favor of promoting greener alternatives such as solar energy. Exxon CEO Rex Tillerson argues that the industry needs these tax breaks and claims the industry earns "windfall profits" are wrong. Moreover, Tillerson says Wall Street traders are running up oil prices beyond the normal variations of supply and demand. Now he has proof to back up his case.

Though people needn't hold a benefit for the Texas oil company, Exxon Mobil's quarter proved that it is not invulnerable. Quarterly profit at the refining and marketing unit fell 63% to $425 million. Profit dropped at Exxon Mobil's downstream unit and at its chemicals business because of the soft economy.

Net income was $9.4 billion, or $1.97 a share, versus $9.25 billion, or $1.85, a year earlier, Exxon said.  It was the smallest profit of 2011. Revenue rose 16% to $121.61 billion. Analysts expected $119.7 billion in revenue. Earnings were a penny under the $1.98 average estimate of analysts surveyed by Bloomberg.

Not much in the way of windfall there.

Jonathan Berr does not own Exxon shares.