President Obama hit the campaign trail Thursday with a warning over a flood of private right-wing groups spending millions of dollars to influence the upcoming midterm elections. Speaking at Maryland’s Bowie State University, Obama cited a recent report from the Center for American Progress that the US Chamber of Commerce has used donations from foreign corporations to target Democratic candidates.

President Obama: “We learned that one of the largest groups paying for these ads regularly takes in money from foreign corporations. So groups that receive foreign money are spending huge sums to influence American elections. And they won’t tell you where the money for their ads come from. So this isn’t just a threat to Democrats. All Republicans should be concerned. Independents should be concerned. This is a threat to our democracy.”