Transcript for Bernie Sanders' Campaign Under Fire Over DNC Data Breach
to have you with us on the eve of the democratic debate. Just hours before greeting the candidates on the stage behind me, a major political firestorm. Bernie sanders, it has been learned that members of his team got access to confidential information. And late today, Hillary Clinton's team weighing in. And Cecelia Vega right here in New Hampshire with me tonight. Reporter: Tonight, accusations of political spy games. Bernie sanders' campaign on the defensive after staffers accessed Hillary Clinton's confidential voter files. In the heat of these campaigns, young people make misjudgments. Reporter: The punishment swift. The democratic national committee cutting off the sanders campaign's access to its massive database. Tonight, outrage from team sanders. That dnc database is the lifeblood of any campaign, a massive list of voters' names, addresses and past voting habits. Each campaign can add their own data for their eyes only. How people might vote, whether they will vote at all, which voters they want to win over. But Wednesday, a software glitch allowed up to four sanders staffers to access Clinton's confidential files. And for 40 minutes, they searched through them 25 times using phrases like "Turnout" and "Primary priority," looking up Clinton's information on crucial states like Iowa, New Hampshire and South Carolina. While some say it's the equivalent of a football team ripping a page right out of the opposition's playbook, the sanders staffer involved says he did nothing wrong. You're saying you never actually saw any of the data that belonged to Hillary Clinton? We didn't use it in any way that we felt could benefit the campaign. Reporter: Yesterday, he was fired. But the story doesn't end there. Late today, the sanders campaign filed suit against the dnc, accusing the party of trying to help Clinton by cutting sanders off from those crucial voter lists. This is unacceptable. Individual leaders of the dnc can support Hillary Clinton in any way they want, but they are not going to sabotage our campaign. Reporter: Tonight, I spoke with dnc chairwoman Debbie Wasserman Schultz. They say that the dnc is in cahoots with Hillary Clinton, and this proves it. And you say what? Well, it's baffling that a campaign that accessed and took information that belonged to another campaign, for what purpose I don't know, but it's baffling that they would say this to us. And what are you hearing from Hillary Clinton's campaign? They're firing back. The campaign chairman calling this an egregious breach. Saying the data was stolen. You know it will come up on the
This transcript has been automatically generated and may not be 100% accurate.