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This story has been updated with a new Associated Press report.

Robby Mook, national campaign manager for Hillary Clinton's White House bid, was bullish on the 2016 campaign during a Star Tribune interview, despite the former Secretary of State's inauspicious start, and the potential candidacy of Vice President Joe Biden.

Mook was in Minnesota last week rounding up delegates at the summer meeting of the Democratic National Committee, where Clinton and her main rivals, including Sen. Bernie Sanders, spoke at a Minneapolis hotel.

"We feel really good about the fundamentals of the campaign," he said, citing record-setting fundraising totals, leads over Republican candidates in national polls, and the beginnings of a ground game that has traditionally been Mook's specialty.

The Clintons got to know Mook while he was Nevada state director during the 2008 campaign, his relentless organizational drive giving Clinton a rare caucus victory during a campaign in which then-Sen. Barack Obama is thought to have out-organized Clinton, especially in caucus states like Minnesota, where Obama won by a two-to-one margin.

Democrats around the country have become audibly nervous about the campaign, as the former New York Senator has spent much of the spring and summer answering questions about the private email server Clinton used as secretary of state. The situation is currently being reviewed by several government agencies, including the Justice Department.

Critics contend by using a private email address and server, Clinton avoided the closer scrutiny that comes from a government email address and the Freedom of Information Act that applies to it. Her opponents have also questioned whether using the private email server was a secure way to communicate.

"The important thing to understand is that (Clinton) in Iowa said she wished she had made another decision, said she should have made another decision," Mook said. "She takes responsibility for that, and she’s fully committed to transparency. That’s why she’s turned over all her emails."

Although Clinton directed staff to give the email server and a backup thumb drive to the Justice Department to review 30,000 emails, another 30,000 were deleted, deemed by Clinton not work-related.

The Associated Press reported Monday that government secrecy and legal analysts say criminal prosecution is unlikely given the known facts, though Republicans will likely continue to use the issue until Election Day.

Mook said it was not on voters' minds.

"When we’re out there talking to voters, they’re not bringing up email servers. They’re talking about child care, how to send their kids to college, how to make their wages grow," he said.

A recent Quinnipiac University poll showed flagging numbers for Clinton, including 51 percent who have an unfavorable impression of her, and 61 percent who say she is not honest or trustworthy.

Mook said he never doubted this would be a tough election and implored Democrats to get involved.

"We’ve got to mobilize and bring as many people into this campaign as possible. Everybody has to get on board and help," he said.