Sen. Elizabeth Warren, D-Mass., responded with a firm "yes" to the question of whether she believed the Democratic National Committee was rigged to favor the presidential nomination of Hillary Clinton.

"Very quickly senator, do you agree with the notion that it was rigged?" CNN's Jake Tapper asked.

"Yes," Warren responded.

Former DNC Chairwoman Donna Brazile said that that the Clinton campaign gained control of the DNC's finances and operations to defeat Sen. Bernie Sanders, I-Vt., in the 2016 Democratic primary, according to a book excerpt published by Politico on Thursday.

Brazile cited "proof" on an agreement she discovered between two Clinton campaign funds and the DNC, in which money would be exchanged for control over DNC finances and strategy.

Tapper asked Warren to speak into the DNC chairwoman's statements.

"We've got to hold this party accountable," Warren told Tapper. "When Tom Perez was elected to chair of the DNC, the very first conversation I had with him was to say, 'You've got to put together a Democratic Party in which everybody can have confidence that the party is working for Democrats rather than Democrats working for the party.'"

"This is a test for Tom Perez," Warren continued. "And either he's going to succeed by bringing Bernie Sanders and Bernie Sanders's representatives into the process, and they're going to say it's fair, it works, we all believe it, or he's going to fail. And I very much hope he succeeds. I hope for Democrats everywhere. I hope for Bernie and all of Bernie's supporters that he's going to succeed.

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