Washington (CNN) Bernie Sanders is battling Hillary Clinton for the Democratic presidential nomination -- but he's defending her trustworthiness, saying the former secretary of state is facing "sexist" criticism.

"I think for a variety of reasons, Hillary Clinton has been under all kinds of attack for many, many years. In fact, I can't think of many personalities who have been attacked for more reasons than Hillary Clinton. And by the way, let me be frank and I'm running against her: Some of it is sexist," Sanders, the Vermont senator, said Sunday in an interview on CBS's "Face the Nation."

His comments come as Clinton pays a political price -- reflected in polling results that show a majority of Americans say she's not honest and trustworthy -- for her use of a personal email address on a private server during her tenure as America's top diplomat, and her family foundation's acceptance of foreign contributions during that period.

Sanders said he's focused on issues like trade and Wall Street reform, and doesn't plan to lodge the same kinds of complaints about Clinton's personal style that many Republican presidential contenders have.

"I don't know that a man would be treated the same way that Hillary is," Sanders said. "So all that I can say is I have known Hillary Clinton for 25 years. I admire her. I respect her. I like her. She and I have very different points of view on a number of issues."

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