In recent attacks, Democrats have criticized Charles and David Koch, billionaire brothers who are also prominent Republican donors, for "fear mongering" and "pouring millions into defeating" Democratic candidates.

"Republicans are addicted to Koch," said Senate Majority Leader Harry Reid this week.

But speaking to an audience of conservative Republicans at CPAC on Thursday, New Jersey Gov. Chris Christie defended the Koch brothers, calling them “two American entrepreneurs who built a business, created jobs and created wealth and philanthropy in this country.”

“Harry Reid should get back to work and stop picking on great Americans who are creating great things for our country,” Christie said.

Through their outside group, Americans For Prosperity, the brothers have already spent upwards of $30 million to boost Republican candidates running during the 2014 midterm election cycle, with particular focus on Senate races. In many key battleground states, such as Louisiana, where Democratic Sen. Mary Landrieu is defending her seat, the money has flowed earlier and more freely than ever before.

To counter the threat, Democrats have adopted the Koch brothers as mascots of the forces they hope to defeat in November and have used the name "Koch" in countless fundraising appeals.