One of the main Democratic super-PACs engaging in House races raised $7.5 million in 2013.
Stone said the group is planning to do battle with the Koch brothers and defend Democrats against GOP attacks, as well as go on offense against vulnerable Republicans.
“House Majority PAC is committed to combatting the efforts of the Koch Brothers and their right-wing allies, who are already stepping up to spend unprecedented sums in House races to promote their reckless agenda,” Stone said.
“Fortunately, as they witness a House GOP seemingly allergic to creating jobs or getting anything done, Democrats are both responding in a big way and recognize the continuing need to be aggressive," he added.
One group affiliated with the Kochs, Americans for Prosperity, has already spent $16 million on attacks against Democratic lawmakers, and House Majority PAC is working to counter some of that offense. The Democratic group just announced plans to launch advertising in Arizona, where Democratic Reps. Ron Barber and Ann Kirkpatrick have come under fire from Americans for Prosperity.
House Majority PAC has also run advertising defending vulnerable Democratic Rep. Nick Rahall (W.Va.) and attacking Republican Reps. Steve Southerland (Fla.), Rodney Davis (Ill.), Mike Coffman (Colo.), Joe Heck (Nev.) and John Kline (Minn.).