Spending by outside groups to influence congressional races surged past the $220 million mark this week, as party committees and conservative groups pumped last-minute cash into ads in advance of the Nov. 2 elections.
The total is roughly twice the $111 million similar groups spent at this point in the last midterm elections in 2006, an analysis by the non-partisan Sunlight Foundation shows.
The money is flowing fast — nearly $80 million in the last week alone — as the political parties and their allies fight for control of Congress.
Many of the most active players, including the U.S. Chamber of Commerce, operate under tax code provisions that do not require them to publicly disclose their donors, even as they spend at an unprecedented rate. A Supreme Court ruling in January freed groups to spend unlimited corporate and union money on independent ads that call for the election or defeat of candidates.
"We are standing at the precipice of unlimited political spending," said Ellen Miller, the Sunlight Foundation's executive director.
Conservative groups have outspent Democrats.
Republican party committees and their allies — including Crossroads GPS, a non-profit created with the help of Republican strategist Karl Rove— pumped nearly $127 million through Thursday afternoon into TV ads, phone calls and mailings, according to the non-partisan Center for Responsive Politics, which tracks campaign money. Democrats and liberal groups spent $92 million.
Groups not aligned with either party reported spending more than $12 million.
Richard Hasen, a campaign-finance expert at Loyola Law School in Los Angeles, said the "staggering" spending is spurred, in part, by the prospect of the Republicans seizing control of the House of Representatives. "When there's a chance of major change, the money comes out."
Hasen said the avalanche of outside money also demonstrates that special-interest groups are prepared to spend heavily in the 2012 fight for the White House. "We may look back at the 2008 (presidential) election and its $4.2 billion price tag as a quaint time when money in politics didn't matter so much," he said.
Republicans need to win 39 seats to capture the majority in the House and a net gain of 10 seats to control the Senate.
The political spending will only grow in the sprint to Election Day. The fundraising arm for House Democrats announced Thursday that it started October with $41.6 million in cash reserves to fund ads and get-out-the-vote efforts. That's twice what its GOP counterpart had stockpiled.
At the same time, a coalition of conservative groups began a $50 million advertising blitz to help GOP candidates who face better-funded Democratic incumbents. The organizations behind the spending include the American Action Network, run by Republican former Minnesota senator Norm Coleman.
"We see ourselves as leveling the playing field," Coleman said. He said voters and donors "are angry about government-run health care, mounting debt, out-of-control spending and stimuluses that spend but don't stimulate jobs."
For their part, Democrats ratcheted up their attacks on the undisclosed money flowing to conservative groups. Democratic National Committee Chairman Tim Kaine said the groups represent "a concerted effort" by Republicans to reverse "a 30-year-trend toward openness and transparency."