WASHINGTON — Campaign spending by groups that don't have to disclose their donors has ballooned to nearly five times the rate of the last election cycle — already topping $23 million this week, new figures provided to USA TODAY show.
The U.S. Chamber of Commerce, the nation's largest business organization, accounts for nearly $12.2 million — or more than half the money that these groups reported spending to influence congressional races in the 2014 election cycle, according to the tally by the Center for Responsive Politics, a non-partisan group that tracks political spending.
The "big money groups are moving faster with an even bigger purse, particularly in the Senate where the stakes are higher," said Sheila Krumholz, the center's executive director. The tally examined spending reported to the Federal Election Commission through Monday and compared it to the same point in previous election cycles.
The political parties and their allies are waging an intense battle for the Senate, where Republicans need a net gain of six seats to win the majority in November and drive the agenda on Capitol Hill.
Chamber of Commerce officials did not immediately respond to interview requests Tuesday but have made no secret of their all-out push to help establishment candidates in key primaries, including next week's contests in Georgia and Kentucky. The business group has spent more than $1 million in Kentucky alone to defend Senate Minority Leader Mitch McConnell, who faces Tea Party-aligned Matt Bevin in the May 20 GOP primary and Democrat Alison Lundergan Grimes in the fall.
Some new groups also have emerged to influence Senate contests.
Oklahomans for a Conservative Future has pumped nearly $650,000 into television and online ads and mailings to promote Republican Senate candidate T.W. Shannon ahead of June's Republican special primary election.
The group was incorporated by two Oklahoma-based lobbyists, Chad Alexander and Stephanie Milligan, and construction company executive Xavier Neira.
Alexander, a former state GOP chairman, said it offers "an avenue for Oklahoma interests' to get involved in the race. He said the organization is operating as a non-profit, rather than a political action committee that discloses funders, because it intends to remain active on conservative issues long after the election.
(Online records show the organization initially registered as a for-profit corporation. Alexander said that was the result of a clerical error in the Oklahoma secretary of State's office.)
Shannon, the state's former House speaker, faces Rep. James Lankford, in the GOP primary to replace Sen. Tom Coburn, who is retiring from Congress. The winner of the June 24 primary is expected to prevail in the general election in November, given the state's large Republican electorate.
Shannon's campaign spokesman Kenneth Bricker declined to comment about the group's activity. "We don't coordinate with them," he said.
Patriot Majority USA, an outside political group aligned with Democrats, has been the second most active organization among "dark money" groups reporting to the FEC, spending nearly $3.3 million — much of it to help protect vulnerable Democratic senators in southern states that backed Republican Mitt Romney in the 2012 presidential contest.
This week, it announced plans to spend more than $700,000 to help defend five House Democrats.
In all, conservative groups now have a more than 2-to-1 edge in dark money spending reported to the FEC six months before the general election, the center's figures show. The tally, however, examines only election-related spending reported to federal regulators and likely will account for a small fraction of all spending to shape the midterms.
A welter of other outside groups don't report their political activity to federal regulators because their advertising does not explicitly call for the election or defeat of candidates.
Among them: Americans for Prosperity, affiliated with billionaire industrialists Charles Koch and David Koch. It already has spent about $35 million to tie vulnerable Senate Democrats to President Obama's health-care law. A budget projection recently obtained by Politico shows the group hopes to spend more than $125 million this year.