Is the DNC tilting toward Hillary Clinton over Bernie Sanders?

The Bernie Sanders campaign has hit a rough patch: The Democratic National Committee has locked campaign staffers out of the data bank of potential voters.

On Wednesday, staff associated with the Sanders camp apparently tapped into a database that contained voter profiles associated with Hillary Clinton's campaign.

The DNC database is meant to be a confidential records system. The DNC has denied the Sanders campaign access to its own data bank of potential voters as a punishment for the breach, a move that Sanders' campaign manager, Jeff Weaver has called an active attempt to undermine the Sanders campaign.

Sanders’ campaign manager, Jeff Weaver, told The Associated Press that because they are no longer able to access their own voter files, while the Clinton camp is able to keep theirs, the DNC is “actively attempting to undermine” Sanders’ bid for the White House.

"In this case it looks like they are trying to help the Clinton campaign," he told Reuters.

Mr. Weaver told AP that the campaign intends to file a lawsuit Friday in order to regain access to their database of potential voters.

The Sanders staffer who made the breach has been fired, but the DNC believes that there may have been more than one staffer who accessed the information and then downloaded and exported it. Officials have said that no voter information was able to enter the public domain as a result of the hack.

The Sanders campaign maintains that the breach was an accidental, isolated incident, and blamed it on the DNC’s software vendor.

"Sadly, the vendor who runs the DNC's voter file program continues to make serious errors,” Michael Briggs, the communications director for the Sanders campaign, told ABC News.

“On more than one occasion, the vendor has dropped the firewall between the data of different Democratic campaigns," Mr. Briggs added. "Our campaign months ago alerted the DNC to the fact that campaign data was being made available to other campaigns. At that time our campaign did not run to the media, relying instead on assurances from the vendor.”

The Sanders staffer who was fired, Josh Uretsky, also maintains that the supposed intrusion was a misunderstanding and that they were only trying to understand the security threats that not having a firewall posed to their own data files.

“The breach was in no way our fault. I saw it and attempted to investigate and attempted to do it in a transparent manner,” he told ABC News. “To my knowledge, we did not take anything out of the system it was in and did not gain anything out of it.”

The incident comes as Sanders struggles to keep pace with Mrs. Clinton. The most recent RealClearPolitics polling data shows Clinton favored in the lead for the Democratic nomination, with 55.9 percent of national support to Sanders’ 30.7 percent.