"It is like a drip, drip, drip. And that's why I said, there's only so much that I can control," she said in an interview on NBC's "Meet the Press." "I can't predict to you what the Republicans will come up with, what kind of, you know, charges or claims they might make."
Clinton likened the inquiries into her correspondence to controversies like that over the Whitewater land deal that trailed her husband's campaign and much of his administration, saying that voters in New York elected her to the Senate despite years of political questions.
The historical comparison marks a new line of defense for Clinton, who has seen her poll numbers fall amid lingering questions about her email usage. Republicans have linked the email issue to past controversies involving the former first lady in an effort to instill doubts among voters about whether she is trustworthy. The email controversy has been a distraction for her presidential campaign in which she faces an unexpectedly strong challenge from Vermont Sen. Bernie Sanders.
"This is just something that has been a regular feature of all our presidential campaigns, except in 2008 for unique reasons," Clinton said. "Ever since Watergate, something like this happens." He added: "We're seeing history repeat itself."
Earlier this week, newly discovered email correspondence between Clinton and retired Gen. David Petraeus when he headed the military's U.S. Central Command, raised fresh questions about whether she truly provided to the government a full record of her work-related correspondence as secretary of state.