This year’s federal election will obliterate spending records for a midterm contest, surpassing the previous high-water mark set in 2006 by about $1 billion, the Center for Responsive Politics predicts less than a week before voters cast their ballots.

That’s enough cash to run the city of Pittsburgh for two years. Buy every resident of Topeka a nice used car. Or treat each and every American to a Big Mac and fries.

And such record-breaking spending is largely fueled by the confluence of two powerful political forces. First, dozens of competitive, often contentious congressional campaigns are being waged, providing incentive for record spending. Second, recent federal court decisions have armed corporations, unions and ideological organizations with the firepower to spend as much as they want, whenever they want on political messages saying just about anything they want, no matter how scathing or partisan.

“We knew this election could make spending history, but the rate of growth is stunning,” said Sheila Krumholz, executive director of the Center for Responsive Politics and its website, OpenSecrets.org. “This kind of money in 2010 makes the 2000 presidential election – hardly a distant memory – look like a bargain at $3.1 billion. And tens of millions of dollars of it is now coming from organizations who, by law, need not disclose their donors. It’s now more difficult than ever for voters to determine whether the outside groups flooding their television and radio airwaves with political messages are doing so for any reason other than promoting their own, narrow set of special interests.”

Republicans have more quickly adapted to this new campaign finance landscape ahead of an election in which they’re angling to recapture the U.S. House of Representatives, if not the U.S. Senate, too. And their potential success at the polls may result in a marked shift in federal policy, painting the U.S. Capitol a bright shade of red after four years tinged with blue.