Some Wall Street executives in line for fat bonuses are akin to mad scientists whose brilliance justifies the size of their pay packages, the head of the U.S. Chamber of Commerce said on Tuesday.

Thomas Donohue, president of the biggest U.S. business lobbying group, said he empathized with public anger at big bonuses paid by banks that also received taxpayer bailouts -- but only up to a point.

There are (compensation) numbers that seem obscene to the average person, and maybe to me, Donohue conceded, in response to a question.

But he said many recipients were being paid in stock and that the amounts reflected that they are very unique kinds of people.

They are like mad scientists, Donohue said at a news conference held to discuss the chamber's legislative priorities. They are all mathematicians, and they are very mobile. They can go to private equity and hedge funds.

Critics seeking to curb excessive pay packages on Wall Street say those incentives led to reckless behavior and contributed to the near-collapse of the economy.

Later Donohue hedged and said the government had the right to go after companies that got bailout funding.

But you have to be careful, he said.

(Reporting by Kim Dixon; Editing by Lisa Von Ahn)