Yet the Chamber, which did not respond to requests for comment on this story, spent even more in previous years. In 2010, it dished out an all-time high $157.2 million on lobbying; 2009 was a close second.

The Chamber's steady growth as a lobbying presence has occurred under the leadership of Tom Donohue, its president and CEO. Donohue, previously the head of the American Trucking Association, took the reins at the Chamber in 1997, at a time when the group was struggling. The next year, Donohue devoted $17 million to lobbying -- a showing not at all shabby for most firms even today. Just six years later, that number had multiplied to $53.4 million, and by 2010, the group's lobbying expenditures exploded to more than eight times the figure a decade earlier.

Although the Chamber employs its own large lobbying force -- in the report filed this week, it lists 88 in-house lobbyists -- it's a major paycheck generator for dozens of outside firms as well. Last year, it was represented by 183 individuals from 33 different lobbying shops. 

Like most lobbying clients, the Chamber has trimmed its spending recently. While it paid out $40.6 million for lobbying in the fourth quarter of 2012, the group devoted a relatively paltry $16.7 million to influencing legislation and regulatory policy in the first three months of this year. And its spending for all of 2012 was down 13 percent from the 2010 peak.

Numbers, of course, tell only part of the story of the Chamber's influence. The organizations it speaks for lend the Chamber much of its credibility in Washington.

"Because of who [the Chamber] represents, I can't believe it wouldn't be effective if they only spent $10 on lobbying," said David Plunkett, a lobbyist at the Center for Science in the Public Interest, a nonprofit that has often been at odds with what's become the biggest force in the lobbying universe. "They represent the major companies of the businesses in this country. Members of Congress are going to listen to those guys."

But the fact that it spends exponentially more gives it a far bigger megaphone.

The impact the group has had over the years is hard to measure, given the number of issues it has been involved in: worker safety, the environment, consumer protection, free trade, labor law, intellectual property, taxes, defense spending -- the Chamber's agenda includes just about any topic that its member organizations have a stake in, which, as it turns out, is quite a long shopping list.

Still, despite its invincible reputation, the Chamber doesn't always come out on top. Despite its initial opposition, the Consumer Financial Protection Bureau is up and running, for example, with a Senate-confirmed director. A major piece of legislation was passed tightening up regulation of the financial industry in the wake of the Great Recession's worst years. And President Barack Obama's health care overhaul was enacted.

Even when the Chamber loses, though, it rarely loses 100 percent. Countless times its efforts have helped shape legislation or regs to be more palatable to the business sector, or kept provisions it viewed as onerous from being adopted. Opponents never count the Chamber out in a battle: It forces a fight when it brings its deep pockets and formidable army to bear. 

Read The Full Report on the U.S. Chamber about Healthcare, Immigration, Enviromental Issues, and Political Elections here.