U.S. Sen. Pat Roberts took to the Senate floor today to defend the Koch brothers amidst an onslaught of recent attacks from Majority Leader Harry Reid, D-Nev.

“Practically every morning, our Leader starts our session by giving a speech personally attacking David and Charles Koch and their families,” Roberts said. “The only thing he seems to do more often than block Republican amendments is attack the Kochs.”

The Koch brothers own Wichita-based Koch Industries, one of the largest privately held corporations in the United States. They also are major funders of such conservative political groups as Americans for Prosperity and Club for Growth.

Roberts, a Kansas Republican, is seeking his third term in the U.S. Senate this year. He faces a primary challenge from Tea Party-backed candidate Milton Wolf, a Johnson County radiologist.

According to a report in CQ Roll Call, GOP lawmakers became particularly outraged this week when Democrats booked the Capitol Visitors Center to host a screening of clips from a new movie, “Koch Brothers Exposed: 2014 Edition,” by filmmaker Robert Greenwald. Republicans say the event may have violated Congressional rules that govern the use of the taxpayer-funded Capitol complex.

Roll Call reported that Reid originally requested to reserve the room to host the screening and a discussion about money in politics, but that request was rejected by congressional committees that oversee the facility. Republicans claim House Minority Leader Nancy Pelosi, D-Calif., resurrected the plan and hosted the event in a separate meeting room at the visitor’s center that is reserved for the House Democratic Caucus.

In recent speeches, Reid has accused Republicans of being “addicted to Koch.” But in his response today, Roberts said that it was Reid who has been obsessing over the Koch brothers.

“The problem with addiction, of course, is that as a tolerance develops, more and more of the drug is needed to satisfy the craving,” Roberts said. “So now we have learned, not only does the Majority Leader spend his mornings attacking the Kochs, he spends his evenings doing so as well.”