The committee touted the number as evidence they'll be able to help their candidates fend off Republican outside groups, which are expected to vastly outspend the Democrats heading into the fall.

"Despite the millions being spent by secret groups around the country, Democrats are working hard to keep the Senate and our supporters are more enthusiastic than ever," said DSCC Executive Director Guy Cecil. "We weren't handed the friendliest map at the start of this cycle, but thanks to strong recruiting, Republican missteps and the influence of the Tea Party in key states, Democrats are optimistic about our prospects heading into November."

The NRSC did not immediately respond to a request for their numbers.